
Class JZli d^-tJ- 

>a/ it 
Book. 



>-y cy _ 



Copiglit]^'- 



COC^RIGHT DEPOSIT. 



WORKS OF 
ANDREW L. WINTON. 

PUBLISHED BY 

JOHN WILEY & SONS, Inc. 



A Short Course in Food Analysis. 

ix + 252 pages, 6 by 9, 107 figures. Cloth. 
$1.50 net. 
The Microscopy of Vegetable Foods. 

With Special Reference to the Detection of Adul- 
teration and the Diagnosis of Mixtures. By 
Andrew L. Winton, Ph.D., with the Collabora- 
tion of Dr. Josef Moeller, Professor of 
Pharmacognosy, and Head of the Pharmacognos- 
tical Institute of the University of Vienna, and 
Kate Barber Winton, Ph.D. xiv +701 pages, 
6f by 10, 635 figures. Cloth, $6.50 net. 

Translation: 
The Microscopy of Technical Products, 

By Dr. T. F. Hanausek. Revised by the author 
and translated by Andrew L. Winton, Ph.D., 
with the collaboration of Kate Barber Winton, 
Ph.D. xii+471 pages , 6i by 10, 276 figures. 
Cloth, $5.00 net. 

Revision: 
Food Inspection and Analysis. 

By Albert E. Leach, S.B.,Late Chief of the U. S. 
Food and Drug Laboratory at Denver. Revised 
and enlarged by Andrew L. Winton, Ph.D. xxi 
+ 1001 pages, 61 by 10, 120 figures, 40 full-page 
half-tone plates. Cloth, $6.50 net. 



A COURSE IN 

FOOD ANALYSIS 



BY 



ANDREW L; WINTON, Ph.D. 

AUTHOR OF THE MICROSCOPY OF VEGETABLE FOODS; REVISER OF 

leach's FOOD INSPECTION AND ANALYSIS; TRANSLATOR OF 

HANAUSEK'S microscopy of TECHNICAL PRODUCTS 



FIRST EDITION 



NEW YORK 

JOHN WILEY & SONS, Inc. 

London: CHAPMAN & HALL, Limited 

1917 



-T^ 






Copyright, 1917 

BY 

ANDREW L. WINTON 



/ 



MAY 10 1917 



pRtBS or 

BRAUNWORTH II CO. 

BOOK MANUFACTUnERI 

BROOKLYN. N. Y. 



/S'a n^ .. / 



PREFACE 



The purpose of this book is first to start the chemical student 
on the right road to the intelligent use of more extensive works 
and thereby become a professional food analyst, and second, to 
meet the needs of the general student who takes up food analysis 
partly for mental and manual discipline and partly because of 
its bearing on subjects such as agriculture, food manufacture, 
nutrition, and household economics. Although the detailed 
instructions may seem more adapted to the wants of the student 
of the second class, whose training may have been limited to 
class room and laboratory work in general chemistry, it is believed 
that no one will find them too explicit. 

The fact that a course in quahtative analysis requires a full 
semester of laboratory work and an abridged course in quanti- 
tative analysis another semester deters many who would other- 
wise avail themselves of the excellent systematic training these 
subjects afford. Such students may find that an introductory 
course in food analysis, requiring but forty laboratory periods 
such as this book contemplates, furnishes not only the requisite 
discipline, but also a general insight into the composition and 
microscopic structure of products needed in everyday life. 

While inorganic methods have a certain degree of sameness, 
being largely based on precipitation or titration, the methods 
of food analysis include extraction, polarimetric, colorimetric, 
centrifugal, and distillation? processes, thus furnishing training 
in versatility. Although the methods selected are but a few of 
those in the Hterature, they are the ones most generally used 
and least Uable to become obsolete through change in trade 
practices or official rulings. After they have been thoroughly 



-aN 



iv PREFACE 

mastered the analyst should be able to undertake at once the 
bulk of the work of most food laboratories. In order that he 
may have a clear conception of the whole subject and be able 
to use intelHgently the literature, the principles of other impor- 
tant methods are briefly considered. 

As some of the apparatus is not ordinarily found in the 
analytical laboratory care has been taken in describing it so 
that it can be accurately specified in ordering from the dealer. 
Lists of apparatus, reagents, and materials for analysis, required 
for the course, are given in the appendix. 

While the chapters are arranged in their logical sequence, 
thus seeking gradually to develop the subject and bring out 
clearly general principles, a rigid adherence to this order by all 
the members of a large class would necessitate the duplication 
of expensive apparatus. To meet this difficulty the matter has 
been so arranged that it can be divided into five sections, each 
of which can be assigned to a group of six students, and thus one 
saccharimeter, one refractometer, one Westphal balance, one 
tintometer, one calorimeter, one polarizing microscope, six 
ordinary microscopes, and certain pieces of multiple apparatus 
be made to do duty for a class of thirty students. 

Although the laboratory work may seem at first sight more 
than can be carried out in the time allowed, the author knows 
from experience that with reasonable diligence on the part of 
the student it can be accomplished in a satisfactory manner pro- 
vided he is not called upon to prepare reagents or standardize 
solutions. 

As an example in ethics too often neglected, if for no other 
reason, care has been taken in describing methods to give the 
names of authors and original references, although unnecessary 
foot notes have been avoided. Analyses of typical foods have 
been drawn from the compilations of Atwater and Bryant, 
Doane and Lawson, Farrington and Woll, Jenkins and Winton, 
and Koenig, also from the bulletins of Frear, Given, and Broomell, 
Merrill and Mansfield, and others. The constants of fats and 
oils are largely those given by Lewkowitsch. 



PREFACE V 

Grateful acknowledgment is also due the author's friends 
Dr. C. A. Browne, Prof. E. M. Chamot, Prof. T. F. Hanausek, 
Prof. Josef Moeller, and others for the use of cuts. Free use 
has been made of matter in Leach's Food Inspection and Analysis, 
both that inserted by Mr. Leach during his lifetime and by the 
author in his revisions. The efforts of friends are thus again 
joined in the same cause. 

Wilton, Conn., 
March, 191 7. 



CONTENTS 



The star designates sections devoted -to laboratory work. 
CHAPTER I 

PAGE 

Introduction 1-9 

Foods: Animal, i; Vegetable, 2; Mineral, 4; Calories, 4. Food 
Analysis: Province; Limitations; Literature, 5; Laboratory Worli, 7; 
Division of Class, 8. 

CHAPTER II 

Dairy Products ". . . .11-31 

Milk: Composition, II ; Colostrum; Value; Standards, 12; Sampling, 
13; *Practice Material; * Specific Gravity, 14; Solids, *Dish Method, 15; 
*Asbestos Method, 16; Fat; *Babcock Test, 18; * Formaldehyde, 20; 
*Ether Extraction, 21; *Calcula ted Solids; * Boric Acid; Protein; Lactose, 
25. Butter: Composition; *Preparation of Sample, 26; *Water; *Fat; 
*Curd; *Ash, 27; Gooch Crucible, 28. Cheese: Composition, 29; 
Analysis, 30. Condensed Milk : Analysis, 30. Ice Cream, 30; Analysis, 
31- 

CHAPTER III 

Meat and Fish 33-40 

Meat, Fish, and Eggs: Constituents, S3', Composition, 34. Meat 
Extracts, 34. Preservatives, 36. *SidpIiur Dioxide, 38. 

CHAPTER IV 

Natural Vegetable Foods and Mill Products 41-81 

Groups of Constituents, 41; Criticism of Methods; *Practice Material, 
42. Composition: Cereals; Legumes; Oil-seeds, 44; Vegetables; 
Fruits; Nuts, 45; Spices, 46. Sample: *Drawing, 46; *Preparation, 
48; *Care of, 49. Moisture: Variation; Consideration of Methods, 50; 
♦Drying in Hydrogen, 52; Method for Spices, 55. Fat: Constituents, 55; 
Principles of Methods; *Ether Extraction, 56; Method for Spices, 59. 
Crude Fiber: Nature, 59; *Henneberg Method, 60. Protein: Nature, 
63; *Kjeldahl Method, 65; Standard Acid and Alkali, 70; Gunning- 
Arnold Modification, 72. Ash: Constituents, 72; *Method, 73. *Nitro- 
gen-free Extract, 74. Starch: Chemical Properties, 74; *Method, 75. 

vii 



viii CONTENTS 



Pentosans, 77. Flour: Testing, 77. Yeast, 78. Baking Powder: 
Constituents, 78; Reactions; *Practice Material, 79; Tests for *Sul- 
phalcs; * Phosphates; *Almnimim Salts, 80; *Starch, 8i. 

CHAPTER V 

Microscopic Examination of Vegetable Foods 83-125 

Introduction: Province, 8.3; Microscope, 84; Microscopic Accesso- 
ries, 85; *Calibration of Micrometer, 86; Mounting, 87; Observation, 
88. Microscopy of Starches: Nature of Starch Grains, 88; *Wheat 
Starch; *Oat Starch; *Bean Starch; *Com Starch; *Potato Starch; 
*Cassava Starch, 92. Typical Foods: *Practice Material, 93; *Wheat, 
04; *Rye, 99; *Oats, 100; *Corn, loi; *Buckwheat, 103; *Peas, 105; 
*Cotton Seed, 106; *Flax Seed, no; *Black Pepper, 112; *Cayenne 
Pepper, 114; *Cinnamon, 115; *Ginger, 116; *CoflEee, 118; *Cocoa, 
120; *Tea, 122. *Mixtures, 122. 

CHAPTER VI 

Saccharine Products 127-138 

Sugar: Characters, 127; Saccharimeter, 128; * Polarization, 130. 
Molasses, S3Tups, and Honey: Composition; *Practice Material, 133; 
*Sucrose by Polarization, 134; '''Solids by Refraction, 135. Maple Prod- 
ucts, 135. Fruit Syrups: Artificial Colors; *Practice Material, 136; 
*Wool Test, 137; *Cochineal Test, 138. 

CHAPTER VII 

Fats and Oils 139-161 

Constitution; Oxidation and Halogen Addition, 139; Saponification, 
140; SolubiUty and Volatility of Fatty Acids, 141. Edible Fats and 
Oils: Constants, 141; *Practice Material, 142; *Spccific Gravity with 
Westphal Balance, 144; ^Refractive Index; Refractometer, 146; *Hal- 
phen Reaction, 150; *Baiidouin Reaction, 151; *Iodine Number, 152; 
'''Saponification Numb r, 155; ''''Volatile Fatty Acids, 157; Polenske 
Number; Other Constants, 159; Hydrogenation, 161. 

CHAPTER VIII 

Fruits, Fruit Products, Liquors, and Vinegars 163-178 

Constituents: Sugars; Acids, 163; Starch; Oil; Fiber; Alcohol; 
Solids, 164; *Practice Material. 165. Fruit Juices: '^Solids, 166; 
'''Sugar, 167; '''Acidity, 168. Wine, Cider, and Other Liquors: Fermen- 
tation, 168; Analysis, 170; Composition, 171; *Alcohol, 172; '''Solids; 
* Acidity, 174. Vinegar: Kinds, 174; Manufacture, 175; Composition, 
176; *Solids; *Acidity, 177. Various Fruit Products: Analysis, 177; 
Preservatives, 177. 



CONTENTS ix 

CHAPTER IX 

PAGE 

Flavoring Extracts 179-201 

Spices vs. Extracts, 179; Nature of Methods, 180. Vanilla Extract 
and Substitutes : Vanilla Beans, 180; Faw///?w; Tonka Beans; Coiimarin; 
Vanilla Extract, 181; Substitutes; *Practice Material, 183; *Hess and 
Prescott Vanillin and Coumarin Method, 184; *Coumarin Melting-point, 
188; *Leach Coumarin Test; Tintometer; *Color Values, 189; *Normal 
Lead Number, 191; *Folin and Denis Colorimetric Vanillin Method, 192; 
Colorimeter, 193; Other Constituents, 196. Lemon Extract: Lemon Oil, 
196; Terpeneless Lemon Extract; *Practice Material, 197; Lemon Oil, 
^Centrifugal Method; *Polariscopic Method; *Citral, 198; Other Con- 
stituents, 200. Orange, Almond, Wintergreen, Peppermint, and Spice 
Extracts, 200. 

CHAPTER X 

Coffee, Tea, and Cocoa 203-210 

Food Value; Stimulating Principles; Caffeine; Theobromine; 203; 
Microscopic Structure, 204. Coffee: Composition, 204; Substitutes; 
*Gorter Caffeine Method, 205; Other Constituents, 206. Tea: Composi- 
tion; Coloring; Facing, 207; Foreign Leaves; Spent Leaves; Analysis, 
208. Chocolate and Cocoa: Composition, 209; Analysis^ 210. 

APPENDIX 

Calculation Tables 211-230 

Temperature Correction of Lactometer Readings, 211. Calculation 
of Total Solids of Milk from Lactometer Reading and Fat, 212. Cal- 
culation of Sugars from Cuprous Oxide, 213. Equivalents of Refractom- 
eter Readings, 222. Calculation of Dry Substance from Refractive 
Index, 224. Temperature Correction for Preceding, 225. Calculation 
of Alcohol from Specific Gravity, 226. 

Lists 231-238 

Apparatus, 231. Reagents, 235. Practice Material, 237. 



A COURSE IN FOOD ANALYSIS 



CHAPTER I 
INTRODUCTION 

Foods are classified as animal, vegetable, and mineral, and 
are divided into subgroups according to their source or method 
of manufacture, factors which are intimately correlated with 
their chemical composition. 

Animal Foods. The Natural Animal Foods include milk, 
eggs, meat, and fish. All of these contain (i) Water, or moisture, 
(2) Crude Fat (or more correctly Ether Extract), (3) Protein 
(nitrogenous substances such as casein of milk, albumin of eggs, 
and myosin of meat), (4) Ash, or mineral matter (chiefly sodium, 
potassium, calcium, magnesium, and iron, combined as phos- 
phates, sulphates, chlorides, and carbonates or in organic com- 
binations), and (5) Carbohydrates (lactose of milk, glycogen of 
meat, etc.). Except in a few foods such as milk and liver, the 
amount of carbohydrates is so small that for ordinary purposes 
it is negligible. Minor constituents, such as Citric Acid of 
milk. Lecithin (phosphorized fat) of eggs. Zoosterols (cholesterol, 
etc.) of fats. Creatine, Creatinine, and Xanthine Bases of meat, 
although of great interest to the physiological chemist, are of 
comparatively small importance to the food analyst engaged in 
nutrition or inspection work. 

Manufactured Animal Foods. Of the dairy products, cream 
is milk with extra fat, cheese is milk with most of the lactose 
(milk sugar), the albumin (soluble protein), and part of the 
water and mineral matter eliminated and salt added, and butter 



2 INTRODUCTION 

is the fat of milk with some water, a trace of casein and mineral 
matter, and added salt. Eggs are usually bought for the con- 
sumer in the shell, although the shell contents, dried or frozen, 
and egg albumin are prepared in considerable amount from the 
cracked and otherwise damaged eggs which accumulate at 
shipping centers. Meat products include sausage and other 
minced foods, lard and edible tallow, which for convenience are 
usually treated in connection with vegetable fats and oils, gela- 
tin, a substance related to the proteins obtained from hoofs, 
hides, etc., and meat extracts consisting in large part of flavoring 
and stimulating substances. Fish products are relatively unim- 
portant. 

Salt and wood smoke are time-honored preservatives for 
meat and fish. Chemical preservatives (formaldehyde, borax, 
boracic acid, sulphites, and sodium benzoate) of late years, 
have come into use, not only in meat and fish, but also in 
milk and dairy products. Artificial colors and in the case of 
canned goods metallic contamination are also met with. 

Vegetable Foods. The Natural Vegetable Foods are classi- 
fied as cereals, leguminous seeds, oil seeds, nuts, vegetables, 
fruits, spices, and alkaloidal products (tea, coffee, and cocoa). 
The constituents of these are divided into six groups: (i) 
Water, (2) Crude Fat (ether-extract), (3) Crude Fiber (cellulose, 
lignin, etc.), (4) Crude Protein, (5) Ash, and (6) Nitrogen-free 
Extract (starch, sugars, gums, organic acids, etc.). All the 
groups but the third are common to both animal and vegetable 
foods although the nitrogen-free extract, which forms the bulk 
of the cereals, leguminous seeds, and many other vegetable foods, 
is a minor constituent of most animal foods excepting milk. 
The third group, crude fiber, is characteristic of vegetable organ- 
isms. It forms the frame work of vegetable cells consisting 
in the young or active tissues of Cellulose and in hardened or 
woody parts of cellulose and " infiltrated " substances such as 
Lignin (woody substance), Suberin (cork substance), Cutin 
(cuticle substance), etc. 

More or less satisfactory methods are available for the deter- 
mination of certain of the individual compounds present in each 



INTRODUCTION 3 

of the six groups as, for example, the different acids and bases 
of the ash, the individual proteins and the Amido Compounds 
of the crude protein, the volatile and non- volatile acids, the 
non-saponifiable matter, including Phytosterols (sitosterol, etc.) 
of the ether extract, and the Starch, Sugars, Pentosans, Dextrin, 
and Organic Acids of the nitrogen-free extract. Some of the 
most important of these methods are described in the chapters 
which follow. 

Spices contain all the six groups of substances enumerated 
but are valuable only for certain Essential Oils or other flavoring 
constituents. Although soluble in ether essential oils are not 
grouped with the fixed (non- volatile) or fatty oils. Being vola- 
tile they pass off with the water on heating, although more 
slowly. 

Alkaloidal foods, unlike spices, are valuable partly for their 
flavoring constituents but chiefly for their stimulating principles, 
Caffeine and Theobromine, which like essential oils can be quan- 
titatively determined. 

Manufactured Vegetable Foods are grouped as (i) cereal 
products (flour, meal, and other mill products), (2) leguminous 
products (pea meal and peanut butter), (3) oil cakes (cotton 
seed, linseed, and other cakes used chiefly as cattle foods), 
(4) vegetable products (pickles, catsup, and canned vege- 
tables), (5) fruit products (jams, jeUies, fruit juices, dried and 
canned fruits), (6) oils and fats, (7) saccharine products 
(sugar, syrup, honey, and confectionery), (8) alcoholic hquors 
(fruit juices, cereal extracts, or other saccharine liquids which 
have been fermented and in certain cases distilled), (9) vinegars 
(alcoholic liquors subjected to acetous fermentation, whereby 
alcohol oxidizes to acetic acid), and (10) flavoring extracts (alco- 
holic solutions of essential oils and other substances). 

In the cereal, leguminous, oil seed, vegetable, and certain 
fruit products determinations of the six groups of constitu- 
ents already dwelt on are of chief importance; in oils and 
fats the so-called chemical and physical constants, including 
Iodine Number, Saponification Number, Volatile Fatty Acids, 
Specific Gravity, Refraction, etc., are determined for purposes 



4 INTRODUCTION 

of identification; in saccharine products determinations of 
sugars are made by polariscopic and chemical methods; in 
alcoholic liquors and vinegars Alcohol and Acetic Acid respect- 
ively are most often estimated; and in flavoring extracts the 
amounts of essential oil, Vanillin, or other aromatic constitu- 
ents are of importance. 

In addition to the chief constituents certain others of minor 
importance are often determined solely as a means of detecting 
foreign admixture. Added colors, preservatives, and metallic 
impurities must often be looked for. 

Chemical analyses of ground or pulped vegetable substances 
serve only to a limited extent in determining their identity or 
purity. Microscopic examination supplies this deficiency. Each 
seed, fruit, root, bark, leaf, and flower consists of more or less 
characteristic tissues and cell contents which can be found under 
the microscope no matter how finely the material may be pul- 
verized. 

Mineral Foods. Although there are a number of mineral 
substances essential for animal life most of these are present in 
sufficient amount in animal and vegetable foods. Salt is the 
one exception. 

Baking powders are semi-mineral foods. They are not, 
however, used for any purpose but to generate carbon dioxide 
gas, which passes off in baking, leaving behind the fixed prod- 
ucts of the reaction. 

Calculation of Calories. The function of foods is partly to 
repair the tissues, for which purpose proteins and mineral salts 
are of chief importance, and partly to furnish fuel for muscular 
energy and animal heat. The fuel value is expressed in calories, 
the unit being the heat required to raise one kilogram of water 
i°C. 

The calories of a given food may be determined by actual 
combustion in a delicate piece of apparatus known as the Bomb 
Calorimeter, or else by calculation from the analysis. Rubner 
uses in his calculations for one gram of each of the three classes 
of nutrients, carbohydrates, proteins, and fats, the factors 
4.1, 4.1, and 9.3, respectively. Calculated to a pound (453.6 



l! 



INTRODUCTION 5 

grams), the fuel value of the carbohydrates and proteins is 
i860 calories each and of the fats is 4218 calories. 

Further details with regard to calories and protein require- 
ments will be found in the works on human nutrition and 
cattle feeding mentioned on p. 6). 

Province and Limitations of Food Analysis. Notwithstand- 
ing the endless number of chemical compounds contained in 
foods, the accurate determination of only a limited number is 
possible with our present knowledge. These limitations of food 
analysis do not seriously detract from its value in the study of 
nutrition, in the identification and commercial valuation of 
foods, and in the detection of adulteration. A few determina- 
tions such as crude fat, crude fiber, crude protein, ash, nitro- 
gen-free extract, sugar, alcohol, acids, chemical and physical 
constants, flavoring principles, and alkaloidal substances are 
sufficient for most practical purposes, while the estimation of a 
limited number of minor constituents serves for finer distinc- 
tions. 

For example the determination of the fat (total glycerides) 
of milk enables the student of dietetics or nutrition to form his 
estimate of the food value due to fats, the dairyman to estimate 
the amount of butter obtainable from the milk, and the food 
inspector to decide whether or not the milk has been skimmed. 
Again the chemical and physical constants of a fat or oil enable 
the commercial or inspection chemist to establish its identity 
or purity without a detailed analysis giving the percentages of 
the different glycerides, were such an analysis possible. 

Literature of Food Analysis. Food analysis has come into 
special prominence in the past generation. During this time 
scientific journals have been established in the leading coun- 
tries, numerous articles have been published in these and other 
journals, and standard works have been written which in some 
cases have gone through several revisions. 

Foods in General. The following works in the English 
language deal especially with the composition and analysis 
of all classes of food: Blyth, " Foods, Their Composition and 
Analysis"; Leach, "Food Inspection and Analysis"; Leff- 



6 INTRODUCTION 

maim and Beam, " Select Methods of Food Analysis "; Wood- 
man, " Food Analysis, Typical Methods and Interpretation of 
Results." Allen's " Commercial Organic Analysis " (Edited 
by Leffmann and Davis) devotes sections to the analysis of 
different classes of foods such as, for example. Dairy Products, 
(Leffmann, Revis and Bolton, Van Slyke); Meat and Meat 
Products (Richardson); Fats and Oils (Mitchell, Archbutt, 
Revis and Bolton); Sugars, Starch and its Isomers (Armstrong) ; 
and Alcoholic Liquors (Baker, Jones, Schhchting, Leffmann). 
The Association of Official Agricultural Chemists publishes from 
time to time the methods of analysis adopted by that body. 

Dairy Products. Farrington and Woll, " Testing Milk and 
Its Products"; Richmond, "Dairy Chemistry"; Van Slyke, 
" Modern Methods of Testing Milk and Milk Products." 

Oils and Fats. Gill, " A Short Handbook of Oil Analysis "; 
Lewkowitsch, " Chemical Technology and Analysis of Oils, 
Fats and Waxes." 

Saccharine Products. Browne, " A Handbook of Sugar Anal- 
ysis"; Long's translation of Landolt, "Optical Rotation of 
Organic Substances "; Rolfe, " The Polariscope in the Chem- 
ical Laboratory "; Weiclmiann, " Sugar Analysis." 

Works on Food Technology. Food analysis is but a hand- 
maiden of more comprehensive subjects, such as food technology, 
nutrition, and food inspection. Of special value to the student 
interested in the agricultural, manufacturing, commercial, and 
sociological aspects of foods are the following: Bailey, " The 
Source, Chemistry, and Use of Food Products "; Tibbies, 
" Foods, Origin, Manufacture, and Composition." 
' Works on Nutrition. Among the works dealing especially 
with human nutrition are the following: Jordan, " Principles 
of Human Nutrition"; Lusk, "The Science of Nutrition"; 
Sherman, "Chemistry of Food and Nutrition"; Snyder, 
" Human Foods and Their Nutritive Value." The nutrition 
of farm animals is treated in Armsby's " Principles of Animal 
Nutrition." 

Analyses of Foods will be found in Atwater and Bryant's 
" Chemical Composition of American Food Materials " and 



INTRODUCTION 7 

Jenkins and Win ton's " Compilation of Analyses of American 
Feeding Stuffs," both published by the Ofhce of Experiment 
Stations of the U. S. Department of Agriculture. 

Outline of the Laboratory Work. The pages which follow 
give general information as to the composition of the principal 
foods, explicit instructions for determining the most important 
constituents which can be carried out in 40 laboratory periods 
of 4 hours each, and brief statements as to other methods 
which, because of their unimportance or complicated nature, 
need not be undertaken by the novice. 

The subjects considered are arranged in 8 chapters, the 
practical laboratory work in each chapter requiring from 2 to 8 
laboratory periods. 

Chapter II (4 periods) describes the determination of solids 
and fat in milk by different methods and tests for preservatives, 
the methods being those commonly followed in valuation and 
inspection. Methods for water, fat, salt, and curd in butter are 
also taken up. Cheese analysis is discussed. 

Chapter III (2 periods) considers briefly the analysis of meat 
products and describes a method of determining the preservative 
sulphurous acid. 

In Chapter IV (8 periods) the determination of water, fat, 
crude fiber, ash, and nitrogen-free extract in ground vegetable 
substances, also of starch in flour are treated at some length and 
the detection of the ingredients of baking powder is considered. 

The microscopic identification of ground vegetable substances 
is taken up in Chapter V (8 periods) . 

Chapter VI (4 periods) describes the polariscopic method of 
determining sucrose and other sugars in saccharine products 
and takes up the detection of adulterants in maple products and 
of colors in confectionery. 

The practical work in Chapter VII (4 periods) includes the 
determination of the principal constants of fats and oils, namely 
specific gravity, refractive index, iodine number, saponification 
niunber, and volatile fatty acids. It also describes the qualita- 
tive tests for cotton seed and sesame oils. 

Chapter VIII (2 periods) traces analytically the transition of 



8 INTRODUCTION 

sugar in fruit juices to alcohol and finally into vinegar and con- 
siders the general analysis of fruit juices, alcoholic liquors, and 
vinegar. 

Chapter IX (5 periods) is devoted to the analysis of flavoring 
extracts, the practical work including the determination of 
vanillin, coumarin, normal lead number, and color of pure and 
imitation vanilla extract, also lemon (essential) oil and citral 
(the oxygenated flavoring constituent) of lemon extract. 

Finally, Chapter X (3 periods) takes up the determination of 
caffeine in coffee, which is also the active principle of tea and, 
together with theobromine, of cocoa products. It also discusses 
other constituents of alkaloidal foods and their determination. 

Suggestions for Division of Class. As has been noted in the 
preface it may be desirable to divide the subject matter and the 
class into groups, thus avoiding duplication of expensive apparatus. 
No little thought has been devoted to this feature of the book. 
In the author's experience, multiple pieces of apparatus, such as 
Kjeldahl digestion and distilling stands, water determination 
apparatus, and centrifugal machines are most convenient when 
arranged for twelve determinations, that is, for duplicate deter- 
minations of six students. That number of students can also 
to best advantage use on the same day apparatus such as the 
polariscope, refractometer, Westphal balance, etc. Accordingly 
it has seemed wise to provide for the division of the class into five 
groups of six students each and for the division of the laboratory 
work also into five groups of methods, taking care that each 
group requires the same number of laboratory periods, namely, 8. 
This plan is readily carried out by assigning to the first group of 
students, Chapters II and VII, to the second group. Chapters 
III, VI, and VIII, to the third, Chapter IV, to the fourth. Chap- 
ter V, and to the fifth. Chapters IX and X, At the end of the 
eighth laboratory period each group of students is assigned a 
new group of methods and so on. 

If more than one student is assigned to a balance there 
will be less interference if each is from a different group. 

Use of Balance, Burettes, etc. No attempt has been made 
to go into the details of construction or the method of using 



INTRODUCTION 9 

the pieces of apparatus found in every analytical laboratory. 
If the student is not familiar with them it is assumed that the 
instructor will arrange for extra periods devoted to such details 
which will naturally extend the time somewhat beyond that 
allowed for the course. 

It is also assumed that reagents and standard solutions will 
be prepared, and the latter also standardized for the class. 
Those who have taken a course in quantitative analysis will 
have had this experience. 

Sections Devoted to Laboratory Work. The subject matter 
of the book is of two kinds: (i) detailed instructions for labora- 
tory Work and (2) general information bearing on the nature, 
composition, and analysis of foods, including brief statements of 
principles involved in methods other than those carried out by 
the student. One without the other would be of Uttle value. 
The chemist who merely learns the mechanical details of analyt- 
ical methods can hardly hope to rise above the grade of a routine 
subordinate; on the other hand the human encyclopoedia of 
chemical knowledge with untrained hands is of even less credit 
to the profession. 

Notwithstanding the equal importance of the two kinds of 
subject matter it has seemed desirable to indicate exactly what 
sections deal with details of laboratory practice to guide both 
the instructor and the student in arranging their time to best 
advantage. For this purpose a five-pointed star (■*■) at the left 
of the sideheading is used. Matter other than that starred can 
be made the subject for recitations. 



CHAPTER II 
DAIRY PRODUCTS 



Milk 

Composition of Milk. Milk, as it is the sole means of sus- 
tenance of the young animal,, must be a perfect food, that is, it 
must contain all the food elements essential for life and in the 
proper proportion. That different animals are furnished by 
nature with different proportions of the different food elements 
appears from the following table: 

Average Composition of the Milk of Different Animals (Konig) 





Woman's Milk. 


Cow's Milk. 


Goat's Milk. 


Fat 

Casein 

Albumin 

Ash 


3-78 
1.03 
1 .26 
0.31 
6.21 


3-64 
3.02 

0-53 
0.71 
4.88 


4-78 
3.20 
I .09 
0.76 
4.46 


Lactose 


Total solids 


12.59 
87-41 


12.78 
87.22 


14.29 
85-71 


Water 




100.00 


100.00 


100.00 



The variation in the milk of different breeds of cows is shown 
in the following table : 

Average Composition of the Milk of Different Breeds of Cows 

(Collier) 





Holstein- 
Friesian. 


Ayrshire. 


Devon. 


American 

Holder- 

ness. 


Jersey. 


Guernsey. 


Fat 

Casein and albumin. . . 
Ash 


3 46 
3-39 
0.73 
4-84 


3-57 
3-43 
0.69 

5-33 


4-15 
3-76 
0.76 
5-07 


3-55 
3-39 
0.70 
5-01 


5-61 

3-91 
0.74 

5-15 


5-12 
3.61 

0.75 

5-II 


Lactose 


Total solids 


12.42 
87.58 


13.02 
86.98 


13-74 
86.26 


12.65 
87-35 


15-41 
84-59 


14-59 
85-41 


Water 




100.00 


100.00 


100.00 


100.00 


100.00 


100.00 



11 



12 DAIRY PRODUCTS 

Colostrum. The foregoing tables of composition do not take 
into account the abnormal milk, known as colostrum, produced 
for two or three days after the birth of the young animal. Colos- 
trum is very high in albumin and consequently in total soHds, 
but is somewhat deficient in lactose (milk sugar) as shown in the 
following analyses of colostrum from twenty cows : 

Average Composition of Colostrum (Engling) 

Fat 3.37 

Casein 4 . 83 

Albumin iS-8s 

Ash 1 . 78 

Lactose 2 . 48 

Total solids .• 28 . 3 1 

Water 7169 



Milk also varies in composition according to the period of 
lactation, the percentage of fat increasing toward the end of the 
period, " Strippings " are also richer in fat than " fore milk " 
or that drawn first from the udder. 

Commercial Value of the Constituents of Milk. While in 
meat the proteins are the most expensive constituents, the fat 
being less highly prized and often wasted, in the case of milk 
the reverse is true, the commercial value being largely deter- 
mined by the amount of fat present. In the form of butter, 
milk fat is worth two or three times as much as other animal fats, 
while skim milk, which differs from whole milk only in that the 
fat is largely removed, is a proverbially cheap food. Because 
of the high commercial value of the fat the determination of this 
constituent is the most important of the analytical processes 
which have been devised and in the buying and selHng of milk 
is ordinarily the only one undertaken. 

Milk Standards. In order to prevent the watering and 
skimming of market milk, as well as to exclude the product 
unduly poor in composition due to breed, individual character- 
istics, and other causes, standards have been fLxed by Federal, 



SAMPLING OF MILK 



13 



MHIM 



State and municipal authorities. The Federal standard, which 
has been adopted by various States and cities, excludes milk 
drawn fifteen days before and ten days after calving and 
requires not less than 8.5 per cent of solids not fat and not 
less than 3.25 per cent of milk fat. 

Sampling of Milk. Proper sampling is very simple but too 
often neglected. An analysis of a sample taken from the bottom 
or the top of milk that has stood long enough for the cream to 
rise is worse than useless. The milk first drawn from the udder, 
like skim milk, is poor in fat, while the last of the milking is 
really cream. Whether the lot of milk be large or small, it 
should be well mixed before sampling. This is accomplished by 
thorough stirring with a dipper, by pouring three times from one 
pail or bottle to another, or, if the quantity is small, by shaking 
in a bottle. Immediately before the sample is 
divided or portions are removed for analysis this 
mixing must be repeated. 

Composite Samples. It is obviously im- 
practicable to mix together the contents of 
several cans and still more so of all the cans of 
a large shipment. In such cases a composite 
sample accurately representing the whole lot may 
be secured by mixing small portions obtained 
from each can after thorough stirring. If the 
cans all contain approximately the same amount 
the portions can be of the same size, otherwise 
to be strictly accurate they should be propor- 
tional to the amount. This latter end is secured 
without calculation by using a sampling tube or 
" milk thief," which takes out a column equal 
in height to the height of the milk in the can. 

The Scovell sampler, shown in Fig. i , has holes 
in a cap at the bottom end which should be 
opened by pushing down before using. The tube 
is then slowly lowered to the bottom of the can, 
allowing the milk which enters through the holes to rise to the 
same level as outside. The holes are closed by pushing the 



Fig. I. — Scovell 
Milk-sampling 
Tube. 



14 



DAIRY PRODUCTS 



cap against the bottom of the can and the milk is delivered into 
the sample bottle. 

A composite sample of the milk furnished from day to day- 
may be secured in the same manner, adding a small amount of 
potassium bichromate as a preservative. Such 
a sample may be tested at the end of a week or 
even a month, 

^Material for Laboratory Practice. For the 
analytical work, a quart of milk, a half pint of 
cream (not over 25 per cent fat), and a pint of 
skim milk should be provided. To the sample 
of milk add 2 to 3 drops of 40 per cent 
formaldehyde solution so that i part of the gas 
will be present in about 20,000 parts of the 
cream. To the sample of skim milk add i gram 
of borax. These preservatives will be tested 
for by well-known methods; they will not in- 
terfere with the quantitative determinations 
undertaken. 

^Determination of Specific Gravity of Milk by 
the Lactometer. Thoroughly mix the sample of 
whole milk as described. Transfer to a glass 
cylinder, insert a Quevenne lactometer (Fig. 2), 
and after the temperature becomes constant let 
each student read the density on the Quevenne 
scale and the temperature on the Fahrenheit 
scale. Correct to 60° F., using the table on 
page 211. 

The readings on the Quevenne scale are the 
figures in the hundredth and thousandth place 
of the specific gravity expressed as whole num- 
bers. For example the reading 31 corresponds to the specific 
gravity i .03 1 . Accordingly to convert Quevenne readings into 
specific gravity prefLx i.o. 

After determining the specific gravity again mix the whole 
milk sample and transfer to as many two-ounce bottles as there 
■¥■ See page 9 for explanation of the use of this star. 



J 



Fig. 2. — Quevenne 
Lactometer. 



TOTAL SOLIDS OF MILK 15 

are students. Stopper each bottle with a clean cork. As only 
fat by the Babcock method will be determined in the cream 
and skim milk samples these need not be divided. 

The specific gravity of milk of standard quality, which ranges 
between 1.02 and 1.035, i^ lowered by watering and raised by 
skimming. While the lactometer may detect one or the other 
fraud, unfortunately it may show a normal reading if both forms 
of adulteration have been practiced. It is accordingly necessary 
to determine, in addition to the specific gravity, the fat and cal- 
culate the total solids or else the total solids and calculate the 
fat. A more certain procedure is to determine both the fat and 
total solids by analysis, using the calculated amounts as a check. 

Duplicate Determinations. The maxim '' Eine Analyse ist 
Keine Analyse" should ever be kept in mind. No analyst, 
however experienced, is infallible. Even the agreement of the 
results by the same analyst is no proof of their accuracy, as 
the same error may have been made in both cases. It is 
therefore desirable in important work that different chemists 
make the determinations, using different reagents or even dif- 
ferent methods. 

The author strongly recommends that all analyses, except 
such few as are specially noted, be carried out by the student 
in dupHcate. If two methods are used for the same constitu- 
ent, as is true of the total solids and fat of milk, one deter- 
mination by each method will suffice. 

^Determination of Total Solids of Milk in an Open Dish. 
The dish should be of thin metal, with a flat bottom. If made 
of platinum the ash can be determined 

after weighing the soHds in the same |i|f||{|^ ^iMiiBlIllk 

dish by heating at dull redness in a '^f^f'^^ 
muffie furnace. Owing to the expense ^--:!!1]Jn^^^^ : ; ; ■ j j i i|||||||p^ 

of platinum it is recommended to ^ ^. , , , ^. , 

. 1 . . Fig. 3. — Tinned Lead Dish, 

use tmned lead dishes, 22 m. m 

diameter and ly^ in. high, such as are made for capping wide- 
mouth bottles; these cost less than two cents each and can be 
thrown away after using (Fig. 3). Aluminum or nickel dishes are 
suitable but cost more. Tin box covers answer the purpose. 



16 



DAIRY PRODUCTS 



Weigh accurately the dish — the use of a desiccator at this 
stage is unnecessary — mix the sample by shaking, and by means 
of a 5 cc. pipette transfer to the dish 5 grams, which will be 
slightly less than the contents of the pipette filled to the mark. 
Although the results are equally as good if any amount from 4 
to 6 grams is used, still in practical work a great amount of 
figuring and possible mathematical error will be avoided by 
using exactly 5 grams, and with little additional labor. 

An error of two or three milligrams in weighing the milk will 
not appreciably affect the result — in fact evaporation, if too 
long a time is taken up in the weighing, will cause a more serious 
error. 

Evaporate on a boiling water bath, using a ring with an open- 
ing only slightly smaller than the bottom of the dish. At the 
end of two to three hours wipe the bottom of the dish dry, place 

in a desiccator while hot, cool fifteen 
minutes, and weigh. Calculate the 
per cent of soHds from this weight. 

The desiccator for food analysis 
(Fig. 4), should be of good size 
(inside diameter at least 6 in.), so 
as to hold several dishes with a 
diameter of 2^ in. These can be 
supported on a circular piece of wire 
gauze, cut to fit the desiccator, or 
on a perforated porcelain plate. 
Three dishes can be arranged in a 
triangle and one placed in the mid- 
dle on top of these. While the 
evaporation is going on proceed according to the following 
method. 

* Determination of Total Solids of Milk by the Asbestos 
Method. This method, devised by Babcock, is really prelimi- 
nary to the extraction of the fat with ether (p. 21). The deter- 
mination of total solids is accordingly incidental and furnishes 
for our purpose a check on the open-dish method. When the 
percentage of fat is obtained by the Babcock centrifugal method, 




Fig. 



-Desiccator with 
Gauze Disk. 



Wire 



TOTAL SOLIDS OF MILK 



17 



the open-dish method furnishes the readiest means of determin- 
ing the total soHds. 

Process. Heat for a minute or two in the flame of a 
Bunsen burner 2 to 2.5 grams of woolly asbestos (free from 
fine and brittle material), and introduce into a hollow cyHnder 
of perforated sheet brass 60 mm. high and 20 mm. in diameter, 
closed 5 mm. from the bottom with a disk of the same material 




Fig. 5. 




Fig. 6. 



Fig. 5. — Perforated Metal Cylinder for Milk Analysis. 
Fig. 6. — Water Oven. 



(Fig. 5). The perforations should be 0.7 mm. in diameter and 
about 0.7 mm. apart. Cool in a desiccator and weigh. Shake 
the whole milk sample, measure out 5 cc. with a pipette, allow 
to deliver slowly on to the asbestos in the cylinder and weigh. 
As there is no means of removing any of the milk after it has 
been added to the asbestos, it is easier to use 5 cc. than exactly 
5 grams. 

Dry in a boiling water or steam oven (Fig. 6), for about four 
hours, cool in a desiccator, and weigh. During the first part 



18 



DAIRY PRODUCTS 



of the drying, the door of the oven should be opened from 
time to time to allow escape of the water vapor. Half of the 
drying can be carried out on the day the portion is weighed 
out, the remainder on the next day before extracting with 
ether. 

While the milk in the open dish and in the perforated cylinder 
is drying make single determinations of fat in the whole milk, 
skim milk, and cream by the Babcock test. 

* Determination of Fat of Whole Milk, Skim Milk, and 
Cream by the Babcock Centrifugal Method 
("Babcock Test"). The apparatus consists of 
a 17.6 cc. pipette for measuring the milk (Fig. 7), 
test bottles with different diameter of neck for 
milk (Fig. 8), skim milk (Fig. 9), and cream 
(Fig. 10), a cyHnder of 17.5 cc. capacity for 
measuring the acid (Fig. 11), and a centrifugal 
machine. The skim-milk bottle has a double 
neck consisting of a larger tube for introducing 
the milk, acid, and water, and a smaller tube for 
measuring the fat. The centrifugal machine may 
be obtained in different sizes holding from 2 to 
40 test bottles, and arranged for hand, steam, or 
electric power. A 12-bottle hand machine (Fig. 
12), answers very well for laboratory use. 

Process. Mix the samples and pipette 17.6 cc. 
(whole milk and skim milk), or weigh 18 grams 
(cream) into the appropriate test bottle. The 
pipette should be rinsed with a few cc. of the 
milk to be tested before measuring out the por- 
tion for analysis. The pipetted portions of the 
whole milk and skim milk will weigh sufficiently 
near 18 grams for practical purposes. Cream, 
Mik~p" ^t*^*''^ however, varies greatly in specific gravity accord- 
ing to its thickness, furthermore it froths and 
clings to the sides of the pipette. In order to insure accurate 
results the test bottle should be weighed before introducing 
the cream and enough cream added to increase its weight 18 



BABCOCK TEST 



19 



grams. The chemical balance may be used, but weighing closer 
than 0.05 gram (about one drop) is unnecessary. 




Fig. 8. 





Fig 9. Fig. 10. 

Fig. 8.— Babcock Milk Test Bottle. 
Fig. 9. — Wagner Skim Milk Test Bottle 
Fig. 10. — Winton Cream Test Bottle. 
Fig. II. — Babcock Acid Measure. 





Fig. ii. 



Fig. 12. — Babcock Centrifuge. 

Introduce 17.5 cc. of commercial sulphuric acid (sp.gr. 1.82 
to 1.84). 



20 



DAIRY PRODUCTS 



3£2A/'>V^ 



In the sample containing formaldehyde note that a violet 
color appears at the juncture of the two liquids, whereas in the 
other samples only a dirty brown color is evident. The violet 
color is dependent on the presence of iron salts in the commer- 
cial acid. The same color is obtained if a portion of the milk 
containing formaldehyde is heated with an equal volume of 
of concentrated hydrochloric acid containing in one liter 2 cc. 
of 10 per cent ferric chloride solution. 

Immediately after adding the acid mix the milk and acid 
thoroughly by a vigorous rotatory motion, holding the test bottle 
by the neck at a slight angle away from the 
body. Much heat is developed and the lirnips 
of curd, which at first form, gradually dis- 
appear on shaking. After shaking each 
bottle place in a pocket of the centrifugal 
machine. If all the pockets are not used 
arrange the bottles symmetrically to avoid 
excessive vibration. If the machine is cold 
it should be heated by a quart or more of 
boiling water. When the machine is full, 
whirl at the rate of 800 to 1000 revolutions 
per minute, according to the diameter of the 
frame, for five minutes. Fill each bottle to 
the neck with boiling water from a wash 
bottle and whirl two minutes longer. Add 
Fig. 13.— Neck of Milk boiling water nearly up to the top gradua- 

Test Bottle, Showing . , . , • ,- , • , 1 • 

Top and Bottom of ^^^^' ^hirl agam for two mmutes, and im- 
Fat Column. merse the bottles nearly to the top of the 

neck in a tank of water at about 60° C. 
Remove one at a time for reading the fat column. Read the 
top of the top meniscus (Fig. 13, 6) and immediately after the 
bottom of the bottom meniscus (Fig. 13, a). The difference 
between the two readings is the percentage of fat. 

Empty the bottles while hot, shaking continually, and clean 
with hot water. 

Although both the milk and the fat are measured the results 
are in percentage by weight. As already stated 17.6 cc. of milk 



FAT OF MILK 21 

weigh approximately i8 grams. The volume corresponding to 
lo per cent of fat on the neck of the test bottle is 2 cc. As the 
specific gravity of the liquid fat is 0.9, 2 cc. corresponds to 1.8 
grams of fat and, therefore, to 10 per cent of 18 grams of milk- 
After the milk or cream is pipetted into the test bottle the 
remainder of the process may be postponed a day or two, as 
souring does not affect the results. When these tests are fin- 
ished the total soHds by the open-dish method can be cooled in a 
desiccator and weighed. 

^Determination of Fat by Extraction with Ether. On the 
next day, while the drying of the milk by the asbestos method 
is being finished, preparations should be made for the extraction 
of the fat with ether. 

Ether extraction, whether of fat in milk or of the crude fat in 
animal or vegetable products, is carried out in a so-called con- 
tinuous extractor, i.e., an apparatus in which the ether, after 
dissolving a portion of the fat of the material and discharging 
into the extraction flask, is volatilized, condensed, and again 
allowed to act on the material, the steps in the process being 
repeated automatically and continuously until the extraction is 
complete. 

The Soxhlet Extractor^ shown in Fig. 14, depends on the inter- 
mittent action of a glass syphon. The ether gradually condenses 
into the extraction tube containing the material until it rises 
to the top of the siphon, when it is discharged into the extraction 
flask. This ingenious apparatus, although well adapted for 
certain purposes, is not thoroughly satisfactory for the deter- 
mination of fat or ether extract, as it is fragile, expensive, employs 
a large quantity of ether, and requires too large an extraction 
flask for accurate weighing. 

The Johnson Extractor ^ (Fig. 15) obviates all these defects. 
The extractor proper E consists of a vertical tube 175 mm, 
long and 26 mm. in diameter (inside measurement), provided 
with a bulge at the bottom, to prevent trapping of the condensed 
ether, and a delivery tube attached at an angle of about 45°, so 
that the condensed ether strikes the neck of the extraction flask 

^ S. W. Johnson, Amer. Jour. Sci., 1877. p. 196. 



22 



DAIRY PRODUCTS 




Fig. 14. 



Fig. 



IS- 



^ ^ , ^^«- 14-— Soxhiet Extractor. 

Fk. .j.-Johnson Fa. Extractor with Perforated Cylinder for Milt Analysis, 



FAT EXTRACTORS 



23 



F, thus avoiding spattering. The extraction flask has a capac- 
ity of 30 to 35 cc. and is attached to the dehvery tube by a 
carefully bored cork. The reflux condenser C is merely an 
ordinary Liebig condenser, set up in a vertical position and 
attached by a bored cork at its delivery end to the extractor. 
The same condenser can be used both for distillation and reflux- 
ing, according to the way it is set up. A support with a suitable 





Fig. 16. 

Fig. 16. — Cork Borers. 

Fig. 17. — Cork Borer Sharpener. 



Fig. 17. 



clamp serves to hold the condenser firmly in position; the 
extractor and extraction flask hang suspended with no support 
other than the corks by which they are attached. The flask 
is heated by a Bunsen flame impinging against a piece of sheet 
metal which rests on a ring attached to the condenser support. 
Instructions. Although only a single extraction of fat in 
milk need be made, the duplicate determination having been 
carried out by the Babcock centrifugal method, two extractors 
cormected with Liebig condensers should be set up, as both will 



24 DAIRY PRODUCTS 

be needed later in the determination of the crude fat in vege- 
table products. In boring holes in the corks (which should 
first be rolled until soft), be sure that the borer (Fig. i6) has a 
keen edge, secured by means of a " cork borer sharpener " 
(Fig. 17), and that it bores a smooth hole into which the tube 
fits without danger of leaking. Do not use a rat-tail file; it 
will be found that one of the borers in a good set, properly sharp- 
ened, will cut a hole into which, without further treatment, a 
given tube will fit accurately 

When the apparatus is set up, place an identification mark 
on the extraction flask. This is best done with a lead pencil 
on an etched or ground spot. The etching fluid, known as 
" diamond ink," applied with a brush, or a few strokes with the 
flat surface of a file moistened with water, gives the desired 
surface. In using any hydrofluoric acid preparation be careful 
not to get any on the skin, as it makes serious wounds. 

Weigh the flask without drying in a desiccator, and without 
a stopper. If special accuracy were important a counter- 
poise flask of the same size but slightly less weight could be used, 
thus obviating the slight error due to the variable amount of 
moisture which condenses on the surface. 

Attach the flask to the lower end of the extractor and place 
the dried and weighed perforated cylinder with asbestos and 
milk solids in the extractor. Pour 8 to 10 cc. of anhydrous 
alcohol-free ether through the cylinder, attach the extractor to 
the condenser, run water through the latter, and heat the flask 
cautiously. Ether free from water and alcohol is required, as 
these would extract sugars and other substances from the residue. 
The ether in the form of vapor passes up through the extractor, 
is liquefied in the condenser, and is returned drop by drop through 
the asbestos into the extraction flask. The fat gradually ex- 
tracted from the milk solids remains in the flask, but the vaporiza- 
tion and condensation of the ether continue without intermis- 
sion as long as the heat is applied. 

After two hours — the end of the laboratory period — the 
extraction is complete. Turn out the lamps, remove the flask, 
and allow to stand until the next day, when the ether should be 



BORAX IN MILK 



25 



driven off over a register or in some other 
warm place and the flask, with the fat, dried 
in the boiling water oven for two hours. Cool, 
weigh, and calculate the percentage of fat. 
Compare with the percentage obtained by the 
Babcock test, also compare the percentages of 
solids obtained by the two methods. 

The percentages of fat by the extraction 
method are accurate to the second place of 
decimals, while those by the Babcock test vary 
from one- to two-tenths of a per cent. For 
ordinary purposes the shorter method is suffi- 
ciently accurate. Practically all the milk and 
cream sold for butter and cheese making in the 
United States are now valued by the Babcock 
test. 

^Calculation of the Total Solids from the 
Specific Gravity and Fat. Given these data a 
close approximation to the true percentage of 
total solids may be obtained from the table 
on page 212 or by the use of the Richmond 
shde rule (Fig. 18). Compare the results thus 
secured with those by direct drying. 

^Testing Milk for Borax and Boric Acid. 
Test the whole milk and skim milk by the fol- 
lowing method: To 10 cc. of the sample in a 
watch-glass, add 6 drops of concentrated 
hydrochloric acid and mix thoroughly with 
a glass rod. Moisten a strip of turmeric 
paper with the mixture and dry on a clean 
watch-glass heated over a water bath. If borax 
or boric acid is present the paper will turn brick 
red, changing to a greenish color with a drop of 
ammonia water. 

Brief Statements of Methods for the Deter- Fig 
mination of Other Constituents of Milk. The 
Protein, including casein and albumin, is obtained 




ToT 



18. — Richmond 
Milk Scale. 

by determin- 



26 DAIRY PRODUCTS 

ing the total nitrogen by the Kjeldahl method (p. 65), and 
multiplying by the factor 6.38. Lactose or milk sugar is esti- 
mated by copper reduction, following the same method as is 
used in the estimation of dextrose (p. 76), but taking into 
account the difference in the reducing power of two sugars. 
Before applying the method it is necessary to remove the 
proteins and fat by precipitation with copper sulphate. The 
proteins form copper compounds which entangle the fat 
mechanically, thus permitting the removal of both classes of 
interfering substances by one filtration. 

Butter 

Composition of Butter. Butter consists of the fat of milk 
mechanically mixed with water, a small amount of casein or 
curd, and added salt. Traces of lactic acid resulting from the 
fermentation of the sugar are also present. The average com- 
position of 350 samples analyzed by Farrington ^ at the Chicago 
World's Fair, is as follows: 

Water 1 1 • 57 

Fat 84.70 

Curd (casein) .95 

Ash (including salt) 2 . 78 



^Preparation of Sample of Butter for Analysis. Place a 
half pound of butter in a pint fruit jar, fasten the cover securely 
in place, and keep in a warm place or in hot water until the butter 
is melted. As lumps of the butter may remain unmelted for 
some time, care should be taken to heat long enough to melt 
completely the whole mass. Without opening, cool the jar 
and contents under a stream of cold water, shaking continually. 
When the mass of butter has solidified, dry off the outside of the 
jar and keep in a refrigerator until needed. The sample thus 
prepared (previous to the exercise) will be homogeneous and 
sufficient for the duplicate analyses of over fifty students. 

* Farrington and WoU: Testing Milk and its Products, 23d ed., p. 259. 



BUTTER 



27 



^Determination of Water, Fat, Curd, and Ash of Butter in 
One Weighed Portion. Weigh two tinned lead dishes, such as 
were used for the determination of total solids in milk (p. 15), 
and place in each dish 2 grams of the butter sample. Dry in a 
boiling water-oven for two and one-half hours, cool in a desic- 
cator, and calculate the loss in weight as percentage of moisture. 

While the dishes are in the oven prepare two porcelain Gooch 




Fig. 19. — Filtering Apparatus for Gooch Crucibles with Chapman Pump. 

crucibles, diameter 35 mm. (Fig. 19 G'), as follows: Connect the 
crucible G by means of a piece of large, thick rubber tubing with 
the filter tube T, the stem of which passes through the rubber 
cork of the tubulated Erlenmeyer flask F, made of thick glass 
so as to resist a vacuum. Connect the tubulature with the 
filter pump P and pour on the crucible a quantity of pulped 
asbestos, suspended in water, sufficient to form a blanket about 
i in. thick. 



28 DAIRY PRODUCTS 

The asbestos used should have previously been chopped into 
small pieces, digested with hydrochloric acid (sp.gr. 1.125) on a 
water bath for an hour or two, and washed by decantation. When 
needed it is shaken with water and removed to the crucible 
while in suspension, using suction. Asbestos prepared for filter- 
ing copper suboxide in sugar analysis may also be used (p. 76). 

Wash once with water and, to facilitate drying, with a little 
alcohol. Dry cautiously over a piece of asbestos paper, finally 
raising the heat to a scorching temperature. Allow to cool, at 
first in the air, finally in a desiccator and weigh. 

To each of the dried residues obtained in the water deter- 
mination add enough gasoline from a wash bottle to about half 
fill the dish and stir carefully with a short glass rod. By means 
of the rod form a lip on the edge of the dish. Pour the gaso- 
lene and any suspended matter onto one of the Gooch crucibles 
connected with the suction apparatus. Repeat the treatment 
several times until the fat appears to have been dissolved, then 
transfer to the crucible all the insoluble matter, using a 
" poUceman," or the ball of the little finger, and a stream of 
gasolene to remove any that may adhere to the dish. When the 
dish is clean, wash down the sides of the Gooch crucible with 
gasolene and continue the washing with several more portions, 
allowing the crucible to empty after each addition. 

Dry the crucible in a boiling water oven for one to two hours, 
cool in a desiccator and weigh. The increase in weight is ash 
(including salt) and curd. 

Ignite cautiously on a piece of asbestos paper, or in a muffle 
furnace, at a dull red heat until the residue is white or gray. 
Cool (finally in a desiccator) and weigh. The loss since the 
preceding weighing is curd (casein), the difference between the 
final weight and the weight of the crucible as first prepared is 
ash, including salt. Calculate both curd and ash in percentages 
of the butter sample. 

The characters of butter fat, as compared with other fats, 
will be considered in Chapter VII. 

The Gooch Crucible used in the preceding and many other 
methods of analysis is a great labor saver in the analytical 



CHEESE 



29 



laboratory. Before its invention it was customary to perform 
all nitrations on filter paper, which not only required more time, 
but necessitated drying of the paper with its contents at ioo° C, 
or else, when the nature of the precipitate permitted, igniting 
in a crucible of the ordinary t>^e until the paper was destroyed. 
In the latter case a correction for the ash of the filter was 
necessary. The Gooch crucible is really a combination of a filter 
and a crucible. It may be obtained made of either platinum or 
porcelain. 

Cheese 

Composition of Cheese. Cheese is prepared by the action 
of rennet (a preparation from calf's stomach) on milk. The 
casein is coagulated and the fat is mechanically held by the 
casein, while the whey, containing the sugar, albumin, and cer- 
tain ash constituents, is drained off. The cheese is finally salted, 
pressed, and cured. The numerous varieties of cheese owe their 
characteristics to the kind of milk used (cow's, sheep's, goat's, 
etc.), the process of manufacture, and the nature of the organ- 
isms introduced. The following table of analyses taken from 
Doane and Lawson's compilation,^ shows the composition of 
common European and American cheese: 

Composition or Cheese 



Brie 

Camembert 

Cheddar (American) 

Edam . . . 

Gorgonzola 

Limburg (American).. . . . 
Neufchatel (American) . . . 
Pineapple (American). . . . 

Roquefort 

Swiss (EmmentaD 

1 U. S. Dept 



Analyst. 


E « 
am 
2 






<u 

.S 




•O'u 

►J 


Balland. . . 


I 


48.80 


22.45 


19.94 


4-85 


BaUand. . . 


I 


49 


00 


21.65 


18.72 


5-95 


Van Slyke 


9 


36 


06 


34-43 


24-45 


0.61 


Patrick . . . 


I 


32 


80 


29.58 


28.41 




Musso. . . . 


7 


37 


30 


34-67 


25.16 


1.62 


Winton . . . 


I 


42 


12 


29.40 


23.00 


0.38 


Winton . . . 


I 


57 


25 


22.30 


15-03 


2.94 


Winton . . . 


4 


24 


07 


38.12 


29-35 


2.49 


Winton . . . 


I 


39 


28 


29-53 


22.62 


1.77 


Benecke . . 


7 


37 


77 


23.92 


30.97 





3 96 
4.68 
3.61 

5-55 
3.82 

5-10 
2.48 

5-69 
6.80 
6.8s 



Agr., Bur. Animal Industry, Bui. 146. 



30 DAIRY PRODUCTS 

Analysis of Cheese. Although laboratory work in the anal- 
ysis of cheese seems beyond the province of this book, a brief 
consideration of the analytical methods should be given. Water 
is determined by drying in an open dish as in the case of milk 
(p. 15) and butter, but the time required is longer. Protein 
is calculated from the nitrogen, as determined by the Kjeldahl 
method, using the factor 6.38. Fat may be determined by a 
modification of the Babcock test or more accurately by ether 
extraction. In the latter case the cheese, as first proposed by 
Short, is ground up in a mortar with anhydrous copper sul- 
phate which is converted into the ordinary or hydrous form by 
the absorption of the water of the cheese, thus obviating the 
necessity of drying. Ash, including salt, is obtained by heating 
below redness. 

Other Dairy Products 

Condensed Milk. Milk concentrated to about half its original 
volume is known as evaporated milk when nothing is added, 
and as sweetened condensed milk when mixed with sugar. 
Ordinarily both products are sterilized and put up in her- 
metically sealed tin cans. 

The Methods of Analysis for the unsweetened product are 
the same as are used for milk, allowing for the greater con- 
centration. 

The presence of sucrose in sweetened condensed milk neces- 
sitates the use of special methods for the determination of fat 
and sugars. The amount of Fat is best found by the Roese- 
Gottlieb method,^ which consists in shaking the milk, after 
adding ammonia water, with a mixture of alcohol, ether, and 
petroleum ether, separating the solvent layer, and evaporating. 
Sucrose is obtained by difference, subtracting the results of 
direct determinations of water, fat, protein, ash, and lactose 
from 100. 

Ice Cream. In addition to milk, cream, and flavors, ice 
cream often contains thickeners, such as gelatin and starch, 
artificial colors, and sometimes chemical preservatives. Homo- 
1 Land. Vers. 1892, 40. 



ICE CREAM 31 

genized (emulsified) foreign oils may be substituted for part 
of the butter fat. 

Methods of Analysis. The Roese-GottUeb method is suitable 
for determining the Fat, which is the most important constit- 
uent. Homogenized Oils are detected by separating the fat 
by Paul's method/ saponifying by the Leffmann and Beam 
method, and distilling the volatile fatty acids. Thickeners 
are tested for by Patrick's method.^ Preservatives and Colors 
are found by the usual tests. 

lU. S. Dept. Agr. Bur. Chem. Bui. 162, p. 118. 
^ Ibid. Bui. 116, p. 26. 



CHAPTER III 
MEAT AND FISH 

Chief Constituents. Lean meat consists essentially of 
Muscle Fibers, Connective Tissues, and Fat Cells. The fibers of 
ordinary meat (Fig. 20) are striated and have a sheath, known 
as the Sarcolemma, made up chiefly of a 
protein related to elastin, insoluble in ordi- 
nary neutral reagents and belonging therefore 
to the albuminoids. Within the sarcolemma 
is contained the meat juice containing sev- 
eral proteins, of which Myosin is the most 
important. 

Elastin and Collagen are the chief con- 
stituents of connective tissue. Gelatin is 
derived from collagen by boiling with 
water and is often classed with the albumi- 
noids. 

Glycogen, a carbohydrate closely related to Fig. 20.— Meat Fiber, 
starch and dextrin, is present in large amounts Magnified. (T. F. 
in liver and in small quantities in meat and 
fish muscle. Other sugars occur in minute quantities. 

Xanthine Bodies, or purin bases {Xanthine, Carnine, Guanine^ 
etc.) closely related to theobromine of chocolate and caffeine 
of tea and coffee, Creatine, Creatinine, and other extractive sub- 
stances, are also present in meat and are characteristic con- 
stituents of meat extracts. 

Fat occurs not only in the fat proper, but also in cells dis- 
tributed throughout the lean portion of the meat. 

Mineral Constituents, such as are contained in milk, are 
also present. 

From these brief statements, it is evident that meat is far 

33 




34 MEAT AND FISH 

from a simple substance. Further consideration of the indi- 
vidual chemical substances would take us within the realm 
of physiological chemistry, where we would find much unex- 
plored territory. For our purpose it is chiefly desirable to con- 
sider the groups of nutritive substances present. As in the case 
of milk, these groups are: (i) protein, (2) fat, (3) ash, and (4) 
carbohydrates. It should be emphasized, however, that while 
milk contains a carbohydrate, lactose, as one of its chief con- 
stituents, animal muscle contains such a small amount of car- 
bohydrate matter that it can, for ordinary purposes, be ignored. 
Composition of Meat, Fish, and Eggs. The table on page 

35 gives the average composition and fuel values of some of 
the cuts of beef, veal, mutton, and pork, fowls, certain species 
of fish and shellfish, and eggs. 

Analysis of Meats. The meat must first be separated into 
lean, visible fat, and bone, and the percentage of each deter- 
mined. The samples of lean meat and visible fat thus obtained 
are then separately analyzed. Suitable methods have been 
published by Grindley and Emmett.^ The soHds may be deter- 
mined by drying at 100° C, as in the case of milk, but more 
accurately by the desiccator method, the fat by ether extraction 
or a centrifugal method, the ash by burning at dull redness, 
and the protein by calculation from the nitrogen. The methods, 
however, do not yield such accurate results as in the analysis 
of milk, owing to the greater difficulties in sampling, the more 
complex composition, and other causes. It is particularly 
difficult to obtain the full amount of fat by ether extraction 
even after long treatment and repeated grinding. As for the 
determination of the minor constituents, the methods are often 
complicated and suited only for special investigations. 

Analysis of Meat Extracts. Micko ^ has devised methods 
for estimating the amounts of the extractive substances noted 
in the preceding paragraphs. Bigelow and Cook ^ and Street * 

^ Jour. Amer. Chem. Soc, 1904, 27, 658; 1905, 28, 25. 
2 Ztschr. Unters. Nahr. Genussm., 1902 et seq. 
3U. S. Dept. Agr. Bur. Chem., Bui. 114. 
^Conn. Agrl. Expt. Sta. Rep., 1908, p. 606. 



COMPOSITION 35 

Average Composition of Meat, Fish, and Eggs (Atwater and Bryant') 



Meat: 

Beef, ribs 

Sirloin steak 

Porterhouse steak . . 

Round steak 

Rump 

Beef liver 

Corned beef, canned 

Veal cutlet 

Mutton, leg 

Mutton, loin 

Pork, ribs 

Ham, smoked 

Bacon, smoked 

Pork, salt, fat 

Fowls 

Fish: 

Bluefish, dressed. . . 

Eels, dressed 

Shad 

Shad roe 

Halibut steak 

White fish 

Trout, brook 

Salmon, canned .... 

Codfish, salt, bone- 
less 

Shellfish: 

Lobster, whole 

Oysters, meats, . . 

Scallops, meats. . . 
Eggs: 

Hen's 



20. 1 
12.8 
12.7 

8-5 
19.0 

7-3 
0.0 

3-4 
17.7 
14.8 
18. 1 
12.2 
8.7 
0.0 

259 

48.6 
20. 2 
50.1 
0.0 
17.7 

53-5 
48.1 
14. 2 

1.6 

61 .7 
0.0 
0.0 



54 

30 
88 
80 _ 

65.5 



20.0 
16. 1 
17.9 
9.2 
18.6 

31 
18.7 

75 
14.5 
31-5 
255 
33-2 

59-4 
86.2 
12.3 

0.6 

7.2 
4.8 
3-8 
4-4 
30 
I . I 

7-5 
0.3 

0.7 

1-3 
o. I 

9-3 



5 V 



14.4 

16. S 
19. 1 
19. 2 
152 
20.2 
26.3 
20. 1 
iS-4 
13 I 
14. 1 

145 
95 
1.9 

13-7 

10. o 
14.8 

9-4 
20.9 

iS-3 

10.6 

9.9 

195 

27.7 

S-9 

6.0 

14.8 

II. 9 



0.7 
0.9 
0.8 
1 .0 
0.8 

1-3 
4.0 
1 .0 
0.8 
0.6 
0.8 
4-2 
4-5 
3-9 
0.7 

0.7 
0.8 
0.7 

1-5 
0.9 
0.7 
0.6 
2.0 

14.7 

0.8 
I . I 
1-4 

0.9 



9.V 



O 



O dj 

■3 p. 
O 



mo 

98s 
mo 

745 
1065 

555 

1280 

690 

900 

1575 
1340 
1670 
268s 
3670 
775 

210 
580 
380 
600 
470 

325 
230 
680 

545 

140 
230 
345 

63 s 



^ The Chemical Composition of American Food Materials. 



36 MEAT AND FISH 

have made extensive investigations of the meat extracts on 
the market in the United States. 

Food Preservatives. Toward the end of the nineteenth 
century the attention of the pubHc was directed to the pres- 
ervation of foods with borax, boric acid, salicyKc acid, sulphurous 
acid, sulphites, and fluorides. Although certain of these had 
,been on the market as household preservatives, their extensive 
use by manufacturers in sausage, Hamburg steak, oysters, 
and other meat and fish foods, also in catsups, preserves, jellies, 
fruit juices, syrups, and dried fruits was not generally known 
until after the passage of State food laws and the publication 
of State reports. 

In order to settle the controversies which arose between 
food officials and food manufacturers, physiological experiments 
were undertaken by government chemists, members of a board 
of consulting scientists appointed by the President, and sci- 
entists representing certain trade interests. The results obtained 
were conflicting, but the findings of the Board were accepted 
by the Secretary of Agriculture as final, and as a consequence 
all the preservatives but sodium benzoate, which had largely 
taken the place of salicylic acid, and sulphurous acid, were 
excluded from foods, and these two were allowed only in limited 
amount and with a declaration on the label. Exception was 
made in the case of foods such as dried codfish, from which 
the preservative could be removed by soaking. 

The Federal decisions were not acceptable to all scientists 
or manufacturers, and as a consequence, bitter controversies 
arose, food officials, physicians, physiological chemists, man- 
ufacturers, and publicists ahgning themselves on one side or 
the other. While the manufacturers using preservatives com- 
plied with the requirement of declaring the presence of the 
preservative in a certain size type, those not using it often 
declared its absence in much larger type. Prominent asso- 
ciations also came out against the use of chemical preservatives. 

The principal arguments in favor of the conservative use 
of chemical preservatives are that they prevent the develop- 



FOOD PRESERVATIVES 37 

ment of dangerous germs, that they permit the marketing of 
foods in a sweet and sound condition which might reach the 
table fermented or otherwise spoiled, that they cheapen the 
cost of foods to the consumer, that they take the place of 
highly flavored and unwholesome products, such as spices, 
wood smoke, etc., and that in the quantities permitted they 
are not injurious to health — benzoic acid, for example, being 
readily eliminated from the body as hippuric acid. 

The arguments against the use of preservatives are that 
they permit the marketing of spoiled food whether or not con- 
taining dangerous germs, that they enrich the producer at the 
expense of the consumer, that they are not, like spices and other 
time-honored preservatives, evident by their taste or odor, 
which of themselves are desirable, and that they are injurious to 
health partly by preventing the proper digestion of foods, owing 
to their antiseptic action, and partly because of their toxic nature. 

Without going further into the controversy it may be stated 
that the determination of benzoic acid and sulphurous acid, 
either free or combined, often demands the attention of the food 
chemist. Sodium benzoate is more commonly used in fruit 
products, such as catsup, jam, and soda water syrup, sulphurous 
acid in dried fruits, and sodium or calcium sulphite or bisulphite 
in meat and fish products. Borax and boric acid are still used 
in dried codfish, but as this food is soaked in water before cook- 
ing, thus removing the preservative, the practice comes within 
a special provision of most food laws. 

The use of sulphites in Hamburg steak and sausage is objec- 
tionable if for no other reason because it permits the marketing 
of decomposed meat, serving not merely as a preservative but as 
a deodorizer. 

Salt, wood smoke, vinegar, spices, and sugar have been used 
as preservatives in meat and fish products, as well as other foods, 
from time immemorial, and they have served in many cases 
where refrigeration, desiccation, and sterilization have not been 
available ; furthermore, they all impart desirable flavors and two 
of them — salt and sugar — are valuable elements of nutrition. 



38 



MEAT AND FISH 



^Determination of Sulphur Dioxide in Hamburg Steak. 
Material for Laboratory Practice. To looo grams of chopped 
round steak add 2 grams of sodium sulphite. Mix thoroughly 
by kneading. 

Apparatus (Fig. 21). 5" is a 500-cc. distilling flask in which 
the substance is placed. It is provided with a double-bored 
rubber stopper through which pass on one side the delivery tube 




Fig. 21. — Apparatus for Determination of Sulphur Dioxide. 



from a carbon dioxide apparatus reaching nearly to the liquid 
in the flask, and on the other a bulb tube B, connected with an 
upright condenser C, both of the latter being the same as used 
for the Reichert-Meissl and Polenske methods (p. 158). At- 
tached to the lower end of the condenser, by means of a piece 
of rubber tubing, is a glass tube of such a length that it reaches 
nearly to the bottom of the receiving flask R. 

The carbon dioxide is generated by the action of dilute hydro- 



SULPHUR DIOXIDE IN HAMBURG STEAK 39 

chloric add (sp.gr. 1.125), delivered from a 125-cc. separatory 
funnel F, on lumps of marble contained in a 250-cc. salt-mouthed 
bottle M. The gas is freed from any possible contamination 
of sulphur dioxide by passing through a wash bottle consisting of 
a 125-cc. salt-mouthed bottle W containing a dilute sodium 
hydroxide solution. The bent tube connecting the two bottles 
passes just through the stopper of M, but nearly to the bottom of 
W. The dehvery tube in S passes about half way to the bottom, 
so that it does not dip below the liquid when the flask is half 
filled. 

Process. Place 50 grams of the mixture of meat and sul- 
phite (weighed on a balance accurate to 0.5 gram) in the flask 
S, add 200 cc. of water, and introduce the stopper with connect- 
ing tubes. Place enough water in the receiving flask R so that 
the dehvery tube dips below the surface and add bromine water 
sufficient to impart a distinct yellow color. 

Partially open the stopcock of F and allow the acid to deliver 
drop by drop on the marble. The flow of carbon dioxide should 
be uniform and at a moderate rate, as shown by the escape of 
the bubbles through the Hquid in W. After running a few min- 
utes to insure the removal of all air, remove the stopper with 
tubes from S and without delay introduce from a pipette 5 cc. 
of a 20 per cent solution of phosphoric acid. The carbon dioxide 
gas, being heavier than air, does not escape from the flask. 
Close the flask immediately, bring to boiling with a Bunsen 
flame, and continue the boiling until the distillate measures 
about 150 cc. If the yellow color of the liquid in the receiver 
disappears, add more bromine, repeating if necessary. The 
carbon dioxide prevents oxidation of the sulphur dioxide which 
would take place in air. 

Carry out a duplicate distillation, using the same apparatus, 
then proceed as follows: 

After the distillation is complete boil the distillate until the 
excess of bromine is removed as shown by the odor, remove to a 
beaker, rinsing with water, and dilute further to about 250 cc. 
Add I cc. of concentrated hydrochloric acid, heat to boiling, 



40 MEAT AND FISH 

and add barium chloride solution drop by drop until the precip- 
itate no longer forms. Allow to stand in a warm place over- 
night or longer. 

Prepare a porcelain Gooch crucible with a compact mat of 
amphibole asbestos, about | in, thick, ignite at bright red- 
ness, cool, and weigh (see page 76). 

After weighing the Gooch crucible place it again in the filter- 
ing apparatus, apply suction, decant the liquid from the pre- 
cipitate of barium sulphate onto the crucible, and finally trans- 
fer the precipitate to the crucible by means of a stream of hot 
water from a wash bottle. Remove any adhering barium sul- 
phate from the beaker, using a " policeman." Wash about five 
times, nearly filling the crucible each time and allowing one 
portion to run through before adding another. Dry at a low 
temperature on a piece of asbestos paper heated by a small 
Bunsen flame, raise the heat cautiously, and finally ignite at 
dull redness for three minutes. Cool in a desiccator and weigh. 

Calculate the percentage of sulphur dioxide (SO2) in the 
material, using the following formula: 

„ 64.06X^X100 _ 

P-— =o.S489a, 

233.43X50 

in which P = the percentage of SO2, 64.06 = 32.06 -f32 = the 
molecular weight of SO2, 233.43 = 137.37 +32.06+64 = the molec- 
ular weight of BaS04, and a = the weight of BaS04 found. 



CHAPTER IV 
NATURAL VEGETABLE FOODS AND MILL PRODUCTS 

Definition. Natural vegetable foods may be defined as 
products that reach the consumer exactly as they are taken from 
the plant, such as grain, seeds, vegetables, fruits, and nuts. 
The constituents present in these also occur in products of 
cereals, oil seeds, leguminous seeds, spices, coffee, cocoa, etc., 
obtained by grinding with or without other mechanical treat- 
ment that changes the amount, but not materially the kind, 
of the constituents, such as sifting to remove bran, press- 
ing to remove a portion of the oil, or roasting to develop 
flavor. 

The Six Groups of Constituents. Since natural vegetable 
products contain the substances essential for animal growth, 
namely proteins, fat, carbohydrates, and mineral salts, together 
with crude fiber and water as incidental constituents, determina- 
tions of the six groups of constituents taken up in Chapter I 
are of first importance. Starch, which makes up nearly all the 
nitrogen-free extract and about 75 per cent of the dry matter of 
the cereals, also sugars and pentosans, which occur widely 
distributed, are frequently determined, although for most 
purposes the amount of nitrogen-free extract answers the re- 
quirements. 

The division into the six groups and the general scheme of 
analysis originated about the middle of the nineteenth century 
with the German agricultural chemists as a basis for feeding 
farm animals. As the general principles of human and animal 
nutrition are the same, analysis of foods for man and beast are 
made by the same methods and expressed in the same terms. 

41 



42 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 

These same methods also serve for food inspection and com- 
mercial food analysis. 

Criticisms of the Methods. Not one of the methods gives 
results which can be expressed in terms of definite composition 
such as is possible in inorganic analysis. Each of the six groups 
contains not only substances related in chemical composition, but 
also others related only in physical properties such as volatility 
or solubility, or in nitrogen content, as will be considered in 
connection with each method. The fact that the tables of com- 
position of both human and animal foods and efficient systems of 
feeding are based on these methods is sufficient reason for their 
continuance. 

Composition of Typical Products. The averages of anal- 
yses of a few common cereal, legume, and oil-seed products, 
used as food for man or cattle, appear in the table on page 44, 
and of vegetables, fruits, and nuts in the table on page 45. 
In addition to the percentages of the six groups of constit- 
uents, the fuel values in calories per pound, calculated as de- 
scribed on page 4, are also given. The materials selected 
are only a few of the hundreds on the market, but are suf- 
ficient to illustrate the range in composition. No analyses of 
bakers' products are included. Ordinary bread has practically 
the same composition as the flour from which it is made, allow- 
ing for water and small amounts of shortening, salt, and yeast 
added. Cake and pastries differ widely in composition, owing 
to the kind and proportion of the ingredients. The average 
composition of spices is given in the table on page 46, and of 
tea, coffee, and cocoa on pages 207, 204, and 209. 

* Material for Laboratory Practice. Any food in the table 
on p. 44, except peanut butter, which, owing to its pasty 
condition is difficult to handle, is suited for analysis by the 
student. Coffee and tea, analyses of which appear on pp. 
204 and 207, may also be used, taking care to note that the 
nitrogen is partly from caffeine and therefore the factor 6.25 
cannot be applied until a correction for the caffeine nitrogen 
has been introduced. Cocoa and chocolate, owing to their 



PRACTICE MATERIAL . 43 

slow filtrations, would better be avoided. Although the same 
methods apply to all these, the experience differs somewhat 
according to the nature of the product. It will add greatly 
to the interest if each student works on a different prod- 
uct, comparing at the end his analysis with those of his 
colleagues. 

The constituents of vegetables, fruits, and nuts are deter- 
mined by the same methods as are employed for cereal and 
allied products, but the preparation of samples of succulent 
vegetables and fruits and of oily nuts necessitates special 
treatment. It is therefore inadvisable for the student to attempt 
the analysis of any of these products except he can devote 
extra time to the work. 

If the student is specially interested in spices and can devote 
a little extra time to his laboratory work, he may analyze one 
of the spices given in the table on p. 46, following certain modi- 
fications of the methods necessitated by the presence of pipcr- 
ine in black and white pepper and of volatile or essential oil 
in all the spices. The modifications required are noted after 
the descriptions of the methods for water, fat (ether extract), 
and protein. Ordinarily it will be found less confusing to con- 
fine the work to products other than spices. 

The results obtained by the student in his analysis will 
difi'er somewhat from those given in the tables, as the prod- 
ucts vary in composition within certain limits, dependent on 
the cultivated variety, locality of growth, season, and process 
of manufacture. It is this variation that makes analyses 
necessary. 

Whatever the material selected, prepare the sample for 
analysis and make duplicate determinations of all the con- 
stituents given in the table by the methods described in 
detail in the following sections. 



44 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 



Average Composition of Cereal, Legume, and Oil-seed Products 



Wheat flour i 

Graham flour ^ 

Rye flour ^ 

Buckwheat flour ^ . . . . 
Corn meal (unbolted) '. 

Oat meal ^ 

Rice 1 

Hominy (Grits) ^ 

Cream of Wheat ^ . . . . 

Force ^ 

Corn flakes' 

Grape Nuts - 

Beans ^ 

Peanut butter ^ 

Wheat bran ^ 

Rye bran ^ 

Linseed meal, old pro.' 
Linseed meal, new pro.' 
Cotton seed meal '. . . . 



12 .42 
13.09 
13.10 

14-55 
14.98 

7.85 
12.44 

13-49 
10. 20 

5 -40 
10 -33 

4. 20 
15.00 

2.04 
II .91 
II .64 

9. 16 
10.07 

8.17 



t5« 



1 .09 
I. 71 
0.84 
1.44 

3-77 



,c6 
35 

44 
20 
40 

31 
10 
62 



46.54 
4-03 
2.81 
7.91 
2.99 

13.08 



o 



0.18 

1.87 

0.41 

0.34 

1 .90 

0.86 

o. 19 

0.32 
0.30 

2 .00 
0.48 
I .90 
3.20 
2. 20 
8.99 

3 48 
8.88 

9-49 
5.62 



10.84 

II .67 

6.65 

6.89 

9.17 

14.66 

7-44 

8.25 

13.20 

11 ,60 
6.50 

12 .60 
20.37 
29.30 
15-42 
14 -74 
32-93 
33-17 
42.31 



0.48 
1.77 
o. 72 
1 .00 
1.42 
2 .01 
0.38 
0.38 
0.40 
2.80 
2.36 
1.80 
3.10 
5-03 
5.78 
3-59 
5-72 
5.82 
7.17 



t: 5 K 



o 0) 
U 



1646 
1624 
1622 
1605 
1643 
1843 
1630 
1613 
1692 
1740 
163 1 

1773 
1728 
2829 
1626 

1643 
1770 
1562 



1 Jenkins and- Winton, Compilation of Analyses of American Feeding Stuffs, U. S. Dept. 
Agriculture, Office Expt. Stations, Bui. 11. 

2 Merrill and Mansfield, Cereal Breakfast Foods, Maine Agri. Expt. Station, Bui. 84. 

3 Frear, Given, and Broomell, Breakfast Foods, Penn. Dept. Agr., Dairy and Food 
Div., Bui. 162, p. 14. 

'Winton, Conn. Agri. Expt. Station., Rep. 1899. P- 138. (Ash includes 4.09% salt) 



Lx 



VEGETABLES, FRUITS, AND NUTS 



45 



Average Composition of Vegetables, Fruits, and Nuts (Atwater 

AND Bryant') 



Vegetables : 

Potatoes 

Sweet Potatoes. 

Onions 

Turnips 

Cabbage 

Lettuce 

Corn, green. . . . 

Peas, green. . . . 

Tomatoes 

Asparagus 

Beans, string. . . 
Fruits : 

Apples 

Oranges 

Bananas 

Peaches 

Raspberries. . . . 

Strawberries . . . 

Watermelons. . . 

Grapes 

Nuts: 

Almonds 

Brazil nuts .... 

Chestnuts 

Cocoanuts 

Peanuts 

Pecans 

Walnuts 



20. o 
20.0 
10. o 
30.0 
150 

150 
61 .0 

45-0 



7.0 

25.0 
27.0 

350 

18.0 

0.0 

S-o 

59-4 
25.0 

45 o 
49.6 
24.0 
48.8 
24 -5 
46.3 
58.1 






O. I 

0.6 

0-3 

O. I 
O. 2 
O. 2 
0.4 
O. 2 
0.4 
O. 2 

0-3 
0-3 

O. I 

0.4 

O. I 

1 .0 

0.6 

O. I 

I . 2 



u 



03 

1 .0 

0.7 
0.9 
0.9 
0.6 

0. 2 
0.9 
0.6 
0.8 

1.8 

0.9 

0.7 
30 

1-3 
31 

1 . I 
2 .0 
1.9 
1.6 



.SX 



1-4 
1.4 
0.9 

1-4 
I .c 
1 . 2 
3.6 
0.9 
1.8 
2. 1 

0.3 
0.6 
0,8 
05 
1-7 
0.9 
o. 2 
1 .0 

II-5 
8.6 
8.1 
2.9 

195 
51 
6.9 



0.8 
0.9 

0-5 
0.6 
0.9 
0.8 

0-3 
0.6 

o-S 
0.7 
0.7 

0-3 
0,4 
0.6 

03 
0.6 
0.6 

0. I 
0.4 

1 . I 

2 .0 

1-7 
0.9 

1-5 
1 .0 
0.6 



y ii X 
2 






310 
460 
205 
125 
125 
75 
180 

255 
105 
105 
180 

220 
170 
300 

155 
310 

175 
60 

335 

1660 
1655 
1425 
1413 
1935 
1846 

1375 



' The Chemical Composition of American Food Materials. 
* Includes crude fiber. 



46 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 



Average Composition of Spices (Winton, Ogden and Mitchell) 



Water. 



Ether Extraci. 



Volatile. 



Non- 
volatile. 



•Sx 

§2 



Ash. 



Total. 



Sand 
(In- 
soluble 
inHCl). 



Black pepper . . . 
White pepper . . 
Cayenne pepper, 

Cinnamon 

Ginger 

Allspice 

Cloves 

Nutmegs 

Mace 



1. 14 
0.73 
1-35 
2.61 
1.97 
405 
19.18 
3.02 
7-58 



8.421 
6.91 ^ 
20.15 
2 . 12 
4. 10 

5-84 

6.49 

36.70 

22.48 



13.06 

3-14 

22.35 

22.96 

3-91 

22.39 

8.10 

251 
3.20 



0.47 
o. 10 

0.15 
0.56 
0.44 
0.03 
0.06 
0.00 
0.07 



^ Includes 6.72% piperine. 

2 Corrected for nitrogen as piperine. 

' Includes 6.11% piperine. 



^Drawing the Sample. It is of the utmost importance that 
the sample of food is carefully drawn and is so prepared for 
analysis that the portions weighed out for the individual deter- 
minations accurately represent the material. Failure to secure 
a proper sample renders the analysis worthless no matter how 
carefully the details of the method are followed. 

It is particularly difhcult to secure a representative sample 
when the quantity of the material is large, such as a ship load 
or several car loads. Such a quantity is seldom uniform through- 
out owing to various causes. For example a cargo of wheat 
may consist of different varieties grown by different farmers 
in different sections. Even the product of the same pro- 
ducer or manufacturer is likely to vary, at least in moisture 
content. 

In order to secure an absolutely accurate sample of such 
a shipment it would be necessary first to thoroughly mix the 
whole product, which would be obviously impracticable. The 
usual procedure is to take portions of the material from dif- 



DRAWING THE SAMPLE 



47 



ferent parts, mix these portions thoroughly, 
and remove suitable samples. 

If the material is in bags a sampling 
tube (Fig. 22), may be used. This consists 
of a brass tube 2 to 3 ft. long in which is a 
slot extending from the conical tip nearly 
to the crosspiece serving as a handle. 
The tube is introduced into the bag with 
the slot on the under side, then turned so 
that the tube can fill, thus securing a core 
the entire length. 

The sampling is best carried out in the 
presence of the interested parties, such as 
buyer or official inspector and seller, and 
the mixed sample divided so that each 
can have a portion for analysis with 
another portion in reserve to go to a dis- 
interested chemist in case of dispute. If 
samples are sent from one party to another 
they should be under seal. 

Samples of a pint or quart are usually 
sufficient, and fruit jars are well suited for 
containers. 

When the product is in retail packages 
such a package may be assumed to be 
representative and true to label and may 
either be taken in its entirety for a sam- 
ple or else mixed and sampled as described. 

The sampling of succulent vegetables 
presents greater difficulties and need not 
be undertaken by the beginner. A quan- 
tity is weighed, sliced or chopped, and 
dried by artificial heat at a moderate tem- 
perature until brittle. Before cooling, the 
dried sample is ground, taking care to 
avoid mechanical loss, again weighed, and Fig. 22.— Sampling Tube. 



48 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 



bottled. In calculating the analysis of the original fresh ma- 
terial, of course account must be taken of the water lost in 
drying. 

The student, after being provided with a sample of one of 
the foods named on p. 44 in a glass-stoppered bottle or fruit 
jar, should proceed as follows: Empty the sample onto a sheet 
of manilla paper and raise one corner after another, thus thor- 
oughly mixing the material. By means of a steel spatula about 




Fig. 23. Fig. 24. 

Fig. 23. — Sieve with Cover and Receiver. 
Fig. 24. — Universal Food Chopper. 

I in. broad remove portions from different parts of the mixed 
substance to a 4-ounce wide-mouth glass-stoppered bottle 
until the latter is filled. This constitutes the subsample which 
is prepared for analysis; the remainder of the sample is held in 
reserve. 

Another way is to divide the sample by halving and quarter- 
ing, botthng each fraction separately. 

^Preparing the Subsample for Analysis. Flour, cocoa, 
most ground spices, and some other foods are in suitable condi- 



CARE OF SAMPLE 



49 



tion for analysis without further preparation except thorough 
mixing; most foods, however, require grinding, so as to pass a 
sieve with a sheet metal bottom having round holes i mm. 
(equivalent to about oV in.) in diameter or one with a bottom of 
No. 20 mesh wire cloth. The sieve should be provided with a 
cover and a receiver (Fig. 23). 

The grinding may be done in an iron mortar, a coffee mill, 
or a " Universal " food chopper (Fig. 24), according to its nature, 
sifting from time to time until all passes through the sieve. 
Care must be taken not to lose any of 
the material during grinding, as that 
would change the composition of the 
sample. 

There are few materials that cannot 
be reduced to a powder with no appa- 
ratus other than a food chopper and an 
iron mortar. The iron mortar should 
be supported on a block which in turn 
rests on a firm support such as a cement 
floor or the portion of a floor over a 
girder of the building. To prevent loss 
of the brittle materials the top may be 
covered with a sheet metal disk with a 
hole in the middle large enough to 
admit the pestle (Fig. 25). Mills and 
other mechanical devices reduce the 
labor of grinding, but great care must 
be taken in cleaning off the adhering material to avoid loss. 
Exposure of the sample and consequent drying must be avoided. 

When ground, mix the subsample thoroughly and bottle. 

'^'Care of Sample. Samples (and subsamples) should be 
kept in tightly stoppered bottles and analyzed as soon as possible 
after grinding. They should not be exposed to heat or to direct 
sunlight which cause the water to evaporate or condense in 
the neck of the bottle or on the inside of the stopper. Care 
should be taken not to jar the sample, which causes dry materials 




Fig. 



25- 



Iron Mortar with 
Guard. 



50 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 

to separate into strata of different densities. Before weighing 
out portions for analysis the contents of the bottle should be 
thoroughly mixed with a spoon (not a spatula), until they appear 
uniform. The portions should be weighed out as rapidly as 
possible to avoid loss or gain of moisture on the balance pan. 

Conditions Affecting the Amount of Moisture in Foods. 
Fresh fruits and vegetables contain more moisture than all the 
other constituents taken together, and the same is true of most 
grains, seeds, leaves, roots, and other products before drying or 
curing. After drying by natural or artificial heat to a sufficient 
degree to insure keeping, the amount of moisture is reduced to 
about 15 per cent or less, depending on the process of drying 
and the humidity of the locality of storage. We speak of grain, 
flour, meal, bran, and other foods as being " air-dry " when 
they are in moisture equilibrium with the surrounding atmos- 
phere. The percentage of moisture of an air-dry material is 
naturally higher when dried in a humid locaHty than in a dry 
one. If stored in tight containers such as tin boxes the mois- 
ture remains practically constant; if stored so as to allow access 
of air it changes somewhat from time to time, but the change is 
very gradual and cannot keep pace with daily fluctuations of 
the atmosphere. 

Flour and meal, as usually milled and unless packed in 
tight containers, lose moisture during storage in most locaHties, 
while roasted coffee, biscuit, and various kiln-dried products 
gain. 

Although a certain amount of moisture is unvoidable, an 
excessive amount is a detriment because (i) it causes spoilage, 
(2) it reduces the percentage of the dry matter or food proper, 
and (3) it unnecessarily increases the cost of transportation. 
Each per cent of excess water is tantamount to a per cent short- 
age in weight. 

Consideration of Methods of Determining Moisture. Most 
of the methods for the estimation of moisture in foods depend 
on the loss in weight on heating. The temperature employed 
varies from 70° C. for saccharine substances containing invert 



METHODS OF DETERMINING MOISTURE 51 

sugar to iio° for various foods. Commonly the temperature 
of boiling water is specified, the heating being carried out in a 
water oven (Fig. 6). The temperature in such an oven even 
near the sea level never reaches ioo° C, being usually 97° to 99°, 
while in high altitudes such as Denver it is considerably lower. 

As exposure to the air of the drying oven causes the oxidation 
of certain oils and other constituents, a gain in weight of such 
constituents offsets the loss in weight due to moisture. To 
obviate this error the drying should be performed in vacuo or 
in a current of dry hydrogen, the former being preferred for 
saccharine substances, the latter for natural foods and mill 
products. 

The loss in weight on heating is not entirely water, as other 
volatile substances evident to the sense of smell are present in 
most foods, although the amount is usually too small to be 
separately determined. Most of the spices, however, contain 
notable quantities of volatile or essential oil which passes off 
with the water. Cloves contain 15 to 25 per cent of an essential 
oil, nutmegs and mace 3 to 10 per cent, and most of the other 
spices smaller quantities. In these it is the common practice 
to determine the total loss at 110° C. and correct the figures 
thus obtained for essential oil separately determined. 

Heating is not always employed to remove the moisture. 
Benedict dries at room temperature in a sulphuric acid desic- 
cator for some days. Grindley hastens the process by gently 
agitating the sulphuric acid during the drying, thus mixing the 
surface film — which soon becomes saturated with moisture — 
with the lower layers. 

Again all methods do not depend on loss of weight after 
removal of moisture. The apparatus of Hoffman and of Brown 
and Duvel, used for the rapid determination of moisture in 
grain, are constructed so that the moisture driven off on heating 
with a petroleum oil in a flask is condensed and measured in a 
graduate. 

The method selected for practice is that of drying at the 
temperature of boiling water in a current of dry hydrogen. It 



52 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 

not only, in the author's opinion, gives the most accurate results 
in the analysis of cereal and oil-seed products, tea, coffee, cocoa, 
and certain spices, such as cayenne pepper and mustard, con- 
taining small amounts of essential oil, but also involves details 
of manipulation particularly instructive for the student. 

^Method of Determining Moisture by Drying in Hydrogen. 
The apparatus (devised by the author ^) is shown in Fig. 26. 




Fig. 26. — Apparatus for Determination of Water by Drying in Hydrogen. 

The weighed portions of the materials are contained in glass 
tubes G which are heated in copper tubes soldered in the 
copper water oven E. 

The oven is 22 cm. long, 18 cm. wide, and 18 cm. high, exclu- 
sive of the legs, which are 18 cm. long. The copper tubes are 
17 mm. inside diameter. The glass drying tubes are not over 
14 mm. outside diameter, fused but not flared at the end, and 



' Conn. Agri. Expt. Sta. Rep. 1889, p. 187. 



MOISTURE BY DRYING IN HYDROGEN 53 

should enter any of the copper tubes of the bath without bind- 
ing. The length to the constriction is 15 cm., the total length 
20 cm. Each end of the tube is provided with a cork. A small 
circle ground or etched with " diamond ink " on each tube 
serves for a lead-pencil number or other identification mark in 
place of gummed labels, which change in weight on heating. 

A stream of hydrogen, purified by passing through nearly 
saturated sodium hydroxide solution in A and dried by c. p. 
concentrated sulphuric acid in 5, is divided into twelve streams 
by means of a U-shaped metal tube with twelve offsets, one of 
the streams passing through each of the drying tubes. In 
order that the hydrogen may be evenly distributed, the mouth 
of each drying tube is fitted with a perforated cork through 
which passes a capillary exit tube of 0.5 mm. bore. The sul- 
phuric acid used for drying the hydrogen falls drop by drop from 
the bulb C over the beads in B into the bottom of the jar, 
from which it automatically siphons out into D. The hydrogen 
passes to the bottom of the jar through a glass tube, bubbles 
through the acid, and rises through the beads, moist with fresh 
acid. The very thorough dehydration of the acid thus effected, 
doubtless, contributes to the accuracy of the results, which in 
flour and meal are about i per cent less than are obtained by 
drying in a dish in the cell of an ordinary water oven. 

Six students should make duplicate determinations in the 
apparatus at the same time. On the day when the samples are 
ground there will be sufficient time to set up the apparatus, 
weigh out the portions into the tubes, and carry out the other 
preliminary details so that the next day can be devoted entirely 
to the drying process. 

The following instructions should be strictly followed to 
insure success: Place in the funnel-shaped portion of the drying 
tubes a small wisp of cotton weighing but a few milligrams. 
Although cotton contains hygroscopic moisture, the amount 
present in such a small quantity will not appreciably affect the 
results. Mix the sample thoroughly in the bottle with an alum- 
inum spoon and weigh out 2 gram portions on a balanced watch- 



54 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 




Fig. 27. — Copper Funnel 
for Filling Drying 
Tubes, Nitrogen Flasks, 
etc. 



glass. If the watch-glasses do not weigh exactly the same, 
place the heavier on the left-hand pan, the lighter on the right- 
hand pan, and balance exactly with the rider. Introduce the 
weighed portions into the drying tubes through a small short- 
stemmed copper funnel (Fig. 27), using a camel's-hair brush to 
remove the last particle from the watch- 
glass and funnel. Weigh the tubes after 
introducing the substance (but not be- 
fore), without the corks, then cork and 
hold until the next day. 

Fill a large Kipp generator with gran- 
ulated zinc and make up a supply of 20 
per cent sulphuric acid ready to be intro- 
duced into the generator the next day. 
The sulphuric acid used in the drying jar 
can be diluted for the generator. Place in ^ a sufficient quan- 
tity of nearly saturated sodium hydroxide solution to cover the 
lower end of the inlet tube, fill C with c. p. concentrated 
sulphuric acid, and see that the bath E contains enough water 
to cover the upper tier of tubes. Connect up the apparatus 
as shown in the cut. 

On the following day, while the bath is heating to boiling, 
add the acid to the hydrogen generator and run for a time to 
expel all air, then pass the gas through A and B into the metal 
U-tube. Uncork the glass drying tubes, insert the corks with 
the capillary outlet tubes, place one after another in the tubes 
of the drying oven, connecting each at the same time with one 
of the offsets of the U-tube. When all are connected draw the 
drying tubes to the left until each outlet tube is well within the 
bath, thus preventing the clogging of the capillary openings with 
condensed moisture, and adjust the hydrogen current so that 
there is a steady and moderately rapid evolution. Adjust the 
stopcock of C so that the acid falls, one drop in about five 
seconds, over the beads. 

After about one hour push the drying tubes toward the 
right so that the substance is well heated and the outer tubes 



MOISTURE IN SPICES 55 

project 2 to 3 cm. Test each by lighting with a match. If 
the capillary openings are clear the hydrogen will ignite, usually 
with a distinct pop, and when the water has been largely expelled 
will burn with a miniature flame. 

Four hours after starting the drying is complete. If, how- 
ever, time is pressing, the tubes can be taken off a half hour 
earlier without appreciably affecting the results. 

Cork each tube immediately after removing from the bath, 
cool fifteen minutes, place the weights on the pan corresponding 
to about lo per cent loss (0.20 gram), remove the cork and 
finish the weighing as rapidly as possible, as the dry substance 
is very hygroscopic. Immediately after weighing cork tightly, 
as the dry material is to be used for extracting with ether. Cal- 
culate the loss in weight as the percentage of moisture. 

Determination of Moisture in Spices. The preceding method 
cannot be used for spices owing to the volatile oil slowly driven 
off at 100°, which clogs the exit tubes. Such products are best 
weighed out into covered aluminum or tin dishes and dried to 
constant weight at 110° C. in a special oven. The loss sus- 
tained is due partly and, in the case of cloves, largely, to 
volatile oils which must be determined as described on p. 59 
and the amount deducted. 

Constituents of the Crude Fat or Ether Extract. The mate- 
rial extracted from dried natural vegetable substances by anhy- 
drous ethyl ether is commonly known as fat or crude fat. A 
more exact term is ether extract, as substances other than fats 
and oils may be present. The composition of the vegetable fats 
and oils of commerce corresponds quite closely with that of the 
ether extract of the seeds and fruits from which they are derived, 
consisting largely of glycerides of the fatty acids with small 
amounts of phytosterol, coloring matter, and other minor con- 
stituents. The ether extract of tea, various pot herbs, hay, 
green vegetables, and other green parts of plants contains the 
blue and yellow coloring substances of the chlorophyl grains 
which impart to the extract a deep green color. Most spices 
contain essential oils and related resins which are soluble in 



56 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 

ether, but only the non- volatile resins remain in the ether extract 
after continued heating. A large part of the ether extract of 
black pepper consists of a crystalline nitrogenous substance, 
piperine. 

Notwithstanding the variety of substances which may be 
present, the ether extract of most staple animal and vegetable 
foods is essentially true fat, i.e., glycerides of fatty acids, and 
the common use of the term fat as a synonym for ether extract 
causes little confusion. 

In the chapter on fats and oils (p. 139), the chemical con- 
stitution of the glycerides will be considered. 

Principles Involved in the Determination of Crude Fat. 
Not only ethyl ether, but chloroform, petroleum ether (purified 
gasolene), and other volatile solvents for fats and oils have been 
used in analytical processes. As the results with the different 
solvents do not always agree, it seems best to chng to ethyl 
ether, which has been used in obtaining most of the results 
recorded in the literature. As in the determination of fat in 
milk, anhydrous alcohol-free ether is employed, and the extrac- 
tion is made on the dry substance, otherwise water- and alcohol- 
soluble constituents, notably sugars, will be extracted. The- 
oretically the extract as well as the substance before extraction 
should be dried in hydrogen to prevent oxidation of the fat, but 
practically this is not necessary, even in the case of the highly 
oxidizable fat from linseed meal, provided the drying is carried 
on only long enough thoroughly to remove the ether. 

^Method of Determining the Crude Fat. The Johnson 
extractor, which was used for the determination of fat in milk 
(p. 21), is best suited for extracting the crude fat from vege- 
table material. In place of the perforated cylinders, however, 
there should be provided inner tubes 135 mm. long and 22 mm. 
in (outside) diameter, with a constriction at the bottom for 
tying on a piece of filter paper backed by cheesecloth (Fig. 28). 
Cover the lower end of the inner tubes with one thickness each 
of filter paper and cheesecloth and fasten securely with strong 
linen thread wound tightly several times around in the constric- 



CRUDE FAT 



57 




Fig. 28— Johnson Fat Extractor. 



58 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 

tion and tied in a hard knot. To prevent the thread slipping 
while tying, first put one end twice around the other and draw 
up taut. The single knot thus formed will remain in place while 
completing the hard knot. Trim off the surplus paper and cloth 
with sharp-pointed scissors, preferably with curved ends. 

Process. Place identification marks on the extraction 
flasks, weigh, and connect with the outer tubes of the extractors. 
Remove the plugs of cotton from the tubes containing the dried 
material remaining after the determination of moisture and 




Fig. 29. — Multiple Johnson Fat Extractor with Heating Closet and Condenser. 



transfer the material to the inner extraction tubes. If any 
appreciable amount adheres to the inner walls of the drying 
tube, brush off with a camel 's-hair brush on the end of a glass rod. 
Shake off also any particles attached to the inner cotton plugs. 
Pour 8 to 10 cc. of anhydrous alcohol-free ether onto the mate- 
rial and connect the extractor with the condenser. Run the 
extraction for three and one-half hours. Turn off the heat, 
remove the inner tubes, and in their place introduce short test- 
tubes. Reserve the extracted residues for crude fiber determi- 
nation. 



MODIFIED METHOD APPLICABLE TO SPICES 59 

On the following day turn on the heat and continue the 
heating until nearly all the ether has been driven off from the 
fat and condensed into the test-tubes. Dry the fat in a boiling 
water oven for one hour^ cool for fifteen minutes, and weigh. 
Calculate the percentage of crude fat. 

Fig. 29 shows a multiple apparatus for carrying on twelve 
determinations at the same time, devised by S. W. Johnson 
and modified by the author. The heating is performed by 
steam pipes, the glass door preventing loss of heat. The con- 
densing tubes are of block tin cooled in a copper tank. 

Modified Method Applicable to Spices. Extract 2 grams of 
the material, without drying, into a flask, which need not be 
weighed. After extraction transfer the ether solution to a 
weighed tinned lead, aluminum, or porcelain dish (p. 15), 
rinsing with ether, and allow to evaporate at room temperature, 
avoiding draughts which cause condensation of water in the 
dishes. Dry overnight in a desiccator and weigh, thus obtain- 
ing the joint weight of volatile and non-volatile ether extract. 
Heat first at 100° C, then at 110° C. to constant weight. The 
loss represents the volatile extract. 

Nature of Crude Fiber. Vegetable tissues consist of cell 
walls and cell contents. The estimation of crude fiber gives us 
an approximate idea of the amount of organic cell-wall material 
which, in active cells, consists largely of cellulose and in older 
tissues of cellulose infiltrated with Hgnin (wood substance), 
suberin (cork substance), or other related substances. Sihca, 
which is found in considerable amount in the straw and grain 
hulls of the cereals, although distinctly a cell-wall constituent, 
is not included in the crude fiber. 

Defined as to the process employed in its determination, 
crude fiber is the substance or substances, other than mineral 
matter, insoluble in ether, boiling dilute sulphuric acid, and 
boiling dilute sodium hydroxide. 

While cellulose is the chief material of the crude fiber, other 
substances are present in variable amount. On the other hand 
all the cellulose is not included, as it is somewhat soluble in the 



60 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 



boiling acid used in the process of determination. Among the 
constituents of crude fiber other than those already named are 
small amounts of nitrogenous substances and pentosans. 

While it is obvious that the term " crude " is significant and 
the crude fiber is a more or less indefinite mixture, still the deter- 
mination is of very great value both in determining the feeding 
value of various materials as well as in detecting foreign sub- 
stances. As " sand " is used to designate the mineral matter 
insoluble in acid, so "crude fiber" serves to describe the organic 
matter insoluble in certain reagents, and it is usually immaterial 
what silicates are present in the sand or what particular cell-wall 
substances occur in the crude fiber. Sand and crude fiber are 
the ingredients of foods of least value because of their insolu- 
bihty. 

■^^The Henneberg Method of Determining Crude Fiber. 
This process,^ followed with few changes through- 
out the world, has come down to us from the 
early days of feeding experiments. It consists 
in boiling 2 grams of the ground material, pre- 
viously extracted with ether, first with i| per 
cent sulphuric acid, which converts the starch 
into soluble sugars and dissolves certain ash 
ingredients, and secondly with i| per cent 
sodium hydroxide, which dissolves such proteins 
as resisted the action of the acid. If the ma- 
terial is not first extracted with ether, which 
treatment is impracticable in certain cases, the 
boiling with alkali saponifies most of the fat, 
the remainder being dissolved by a final wash- 
FiG. 30.— Weighing jng with ether. The crude fiber contaminated 

Bottle with Filter •.-, . ^ i. • j • i j • i 1 t^ 

T. r /- 1 With mmeral matter is dried and weighed. It 

Paper lor Crude ^ _ ° 

Fiber. is then burned and the weight of the residue of 

mineral matter deducted. 
Process. Place in each of two cylindrical weighing bottles, 
75 mm. high and 40 mm. in diameter, without a constricted 
^ Land. Vers., 6, p. 497. 




CRUDE FIBER 61 

neck, a rolled-up ii-cm. filter paper folded ready for use and 
bearing a lead-pencil mark corresponding to that on the bottle 
and its stopper (Fig. 30). A lead pencil can be used on the 
ground surface of both the bottle and the stopper, thus avoid- 
ing permanent marks or numbers. Remove the stopper and 
place in a boiling water oven to dry. 

Measure 200 cc. of water from a graduate into each of two 
500-cc. Erlenmeyer flasks and mark the level with a gummed 
label. Remove from the extractors the inner tubes, containing 
the residues from the determination of ether extract, and allow 
the ether to evaporate. Empty the dry residues into the flasks 
and brush out any that may adhere with a camel's-hair brush 
on the end of a glass rod. All this should be done on the day 
when the extraction is performed as the crude fiber process, 
owing to the slow filtration after boiling with acid, is liable to 
require all the time of one laboratory period. 

Heat a little more than 400 cc. of ij per cent sulphuric acid 
solution and when the boiling-point is reached immediately pour 
into the two Erlenmeyer flasks up to the 200-cc. mark. Without 
delay heat over a gauze with a moderate-size flame, taking care 
to watch the flasks constantly and lower the flame to the smallest 
possible size at the first indications of boiling. If the liquid is 
allowed to boil vigorously it is almost sure to froth over and 
without warning thus ruining the determination. . A glass 
tube bent at right angles at the end (Fig. 31), devised by Far- 
rington, should be at hand so that a blast of air from the mouth 
can be instantly directed into the flask to prevent frothing. 
In order to reduce the flame to a small size without snapping 
down, the top of the Bunsen burners should be covered with 
caps of wire gauze (Fig. 32). It is well to keep gauze caps on 
all the burners used in food work, as low flames are often em- 
ployed. 

Keep the flames adjusted so that the liquid boils very gently 
and continue the boihng exactly thirty minutes. If these 
precautions are observed, not only will there be httle danger 
of frothing over, but the substance wiU not crawl up far on the 



62 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 

sides of the flask where it would be washed by condensed 
water and not subjected to the action of the acid. Any small 
amount that may crawl up may be brought down by very 
gentle rotation of the flask. Concentration of the acid will also 
be avoided and quite as effectually as by the use of a cumber- 
some reflux condenser recommended by some chemists. 

At the end of the thirty minutes filter without delay on i i-cm. 
papers, selecting a quahty known to filter rapidly. Keep the 





Fig. 31. 



Fig. 32. 



Fig. 31. — Flask and Tube for Crude Fiber Determination. 
Fig. 32. — Bunsen Burner with Wire Gauze Cap. 



papers well filled with liquid. If they clog to such an extent 
that the filtration cannot be finished in say an hour, use a second 
paper or even a third. Rinse the flask once only, using a few 
cc. of hot water, but do not attempt to remove all the substance 
to the paper. The water used to rinse the flask is sufiicient to 
wash the paper. 

When the filtration is nearly finished heat to boiling in a 
beaker a little over 400 cc. of ij per cent sodium hydroxide 
solution. Spread out the paper (or papers), on a 12. 5 -cm. fun- 



NATURE OF THE PROTEINS 63 

nel and rinse with the hot alkah back again into the flask used 
for the acid boihng. The alkah speedily removes the sub- 
stance from the paper, leaving sufficient to rinse the funnel and 
wash down the sides of the flask. When the level of the mark 
on the flask is reached, heat to boiling and boil gently for thirty 
minutes exactly as in the acid boiling. As frothing during the 
alkali boiling is likely to take place with scarcely any warning, 
it is necessary carefully to control the heat and keep constant 
watch. 

After fifteen minutes' boiling remove the weighing bottles 
with filters from the water oven, stopper, and at the end of 
the boiling, after they have cooled fifteen minutes, weigh them. 

Filter on the weighed papers, rinse all the materials out of the 
flasks, and wash thoroughly on the papers, using hot distilled 
water. The alkali filtration of most substances proceeds rapidly. 
After the washing with hot water has removed the alkah as 
tested with litmus paper, wash twice with 95 per cent alcohol 
and three times with ether, taking care to direct the stream into 
the fiber, otherwise it may not penetrate the mass. Remove- 
the funnels from the flasks and keep overnight in a warm room 
to facihtate evaporation of the ether. 

On the next day, if there is no evidence of moisture in the 
fiber, carefully transfer the papers with fiber from the funnels to 
the weighing bottles, dry in the boiling water oven for three 
hours, stopper, cool fifteen minutes, and weigh. 

Wrap each filter paper closely about the fiber and burn to 
whiteness at a bright red heat in a porcelain capsule or crucible. 
When cool the ash may be readily brushed off from the crucible 
and weighed on a balanced watch-glass. Correct the weight 
of this ash for any ash in the paper and deduct the weight thus 
corrected from the weight of the crude fiber. Calculate the 
percentage of crude fiber. 

Nature of the Proteins. The proteins, formerly known as 
the albuminoids and later as the proteids, are alike important 
in vegetable and animal physiology. In addition to carbon, 
hydrogen, and oxygen, which are the only elements contained 



64 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 

in the carbohydrates and fats, and which are built up by the 
plant from carbon dioxide taken in through the leaves from the 
air and water absorbed by the roots from the soil, all the pro- 
teins contain nitrogen, the most valuable constituent of soils 
and fertilizers. Most of them contain sulphur and some of them 
phosphorus. The earlier vegetable physiologists believed that 
only nitrogen combined as nitrates formed usually by the " nitri- 
fication " of other nitrogenous compounds was available for 
plants. The classical researches of Hellriegel showed, however, 
that atmospheric nitrogen was readily utilized by leguminous 
plants (peas, beans, clovers, etc.), through the agency of bac- 
teria residing in the root nodules of these plants. The proteins 
derived directly or indirectly from plants serve in the animal 
body not merely as fuel for keeping the body warm and carry- 
ing on various muscular activities — the chief role played by the 
carbohydrates and fats — but also to make nerve and muscle. 
While the carbon is eliminated as carbon dioxide through the 
lungs, the nitrogen is excreted by the kidneys as urea. 

Although the earlier chemists determined the percentages 
of nitrogen, carbon, hydrogen, oxygen, and sulphur in the pro- 
teins and learned that their molecular weights were very high, 
the real constitution of these substances remained a mystery 
until Fischer showed that they are complex compounds of 
amino acids, the so-called " building stones," which can be split 
off by special processes. This work and that of Osborne, in the 
United States, who has obtained crystals of certain proteins, 
have placed this complex group on a definite scientific basis. 

While the quantitative separation of the individual proteins 
is rarely possible, the fact that all of them contain approximately 
1 6 per cent of nitrogen enables the analyst to calculate the 
percentage of protein from the nitrogen content using the factor 
6.25. The results thus obtained should be properly designated 
" crude protein," partly because the nitrogen content of the dif- 
ferent proteins varies considerably and partly because other 
nitrogenous compounds such as amides (i.e., asparagin), and 
alkaloids (i.e., caffeine and piperine), are often present. 



KJELDAHL METHOD 



65 



^Determination of Crude Protein by the Kjeldahl Method. 

Apparatus, (i) Digestion Stand. The multiple apparatus 
shown in Fig. 2)3 consists of a cast-iron stand, a horizontal 
lead pipe for carrying off the fumes, and a battery of Bunsen 
burners. 

If special apparatus is not available, the digestions can be 
made on ordinary lamp-stand rings over individual burners. 
The flask may be supported on a pipestem triangle, resting on 




Fig. 33. — Multiple Digestion Stand for Kjeldahl Nitrogen Determination. 



the ring, and the neck inclined at the proper angle against a 
clamp swung around to one side. The operation should be 
carried out in a hood with a good draught or Sy's suction device 
for removing the fumes from each flask employed. 

(2) Distilling Apparatus. Fig. 34 shows the Johnson mul- 
tiple distilling stand with copper tank condenser and block 
tin tubes. At the left are shown bottles with swinging 
tubes for measuring the potassium sulphide and sodium 
hydroxide solutions which are not essential in the student 
laboratory. 



66 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 

Lacking the special outfit the apparatus shown in Fig. 21, 
after removing the carbon dioxide delivery tube from the 
flask and closing the hole with a piece of glass rod, will answer 
the purpose. 

(3) Burettes. Two 50-cc. burettes, one with a ball cock 
for the standard alkali, the other with a glass stopcock for the 
standard acid, are shown in Fig. 35. 

The ball cock consists of a piece of black or red rubber 



Fig. 34. — Multiple Johnson Distilling Apparatus for Kjeldahl Nitrogen 
Determination. 

tubing closed by a glass bead som.ewhat larger than the inner 
diameter of the tubing. When pressed between the thumb and 
first finger passages are formed on opposite sides of the ball, 
allowing the liquid to run out. This form of cock is inexpensive, 
permits an accurate control of the flow, and avoids the 
cementing action of alkali on glass stopcocks. 

The glass stopcock needs no explanation. To avoid the 
danger of the ground parts of burettes, separatory funnels, 
etc., becoming interchanged, lost, or broken, each may be 



KJELDAHL METHOD 



67 



attached to its apparatus, as proposed by the author, by means 
of a small brass chain (Figs. 35, 93, and 104). 

Fig. 36 shows the Squibb form of burette attached to a 
glass bottle containing the standard solution. 




gen. 



Fig. 35. — Burettes with Ball and Glass Stopcocks. 

Reagents, (i) Concentrated Sulphuric Acid free from nitro- 
1. 

(2) Standard Tenth-normal Hydrochloric Acid. 

(3) Standard Tenth-normal Sodium Hydroxide Solution. 

(4) Sodium Sulphide Solution, 40 grams per liter. 

(5) Sodium Hydroxide Solution, nearly saturated. 



68 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 



(6) Red Oxide of Mercury. 

(7) Potassium Permanganate. 

(8) Metallic Zinc, granulated, 
20 mesh. 

(9) Cochineal Tincture. Di- 
gest 30 grams of the powdered 
bugs for some days in the cold 
with a mixture of 250 cc. of 95 
per cent alcohol and 750 cc. of 
water, and filter. 

Process. Weigh out i gram 
of the substance on a balanced 
watch-glass and transfer to a 
600-cc. flat-bottom flask of the 
Jena type, add about 0.7 gram 
of red oxide of mercury (which 
can be measured from a small 
copper cartridge shell cut off to 
the proper length and provided 
with a wire handle), and 20 cc. 
of concentrated sulphuric acid 
free from nitrogen. Digest on 
the special stand shown in Fig. 33 
at first with a low flame. The 
suffocating fumes of sulphurous 
acid, which are given off in large 
quantities during the first part 
of the heating, are carried off 
by the lead pipe into which the 
necks of the flasks enter through 
holes. After the densest of the 
fumes have been given off (fif- 
FiG.36.-Squibb Burette with Filling ^^^^ ^^ ^^ minutes), raise 

Device. , , ... . , 

the heat to the boilmg-pomt but 
avoid a flame high enough to impinge against the flask above 
the Hquid. Continue the digestion until the liquid becomes 




KJELDAHL METHOD 69 

light yellow, which requires usually two to three hours, turn ofif 
the flame and add from a small spoon, with gentle shaking, 
small quantities of potassium permanganate until a permanent 
brown or green color is acquired by the liquid. Great care 
should be exercised in handhng the flask, as the boiling-point of 
the acid is about twice that of water. The nitrogen of the 
material will be completely converted into ammonium sulphate. 

The remainder of the process can be finished on the next day. 
While the digestion is going on determinations of ash can be 
started. 

On the next day add to a pint milk bottle from a burette 
an exactly measured quantity of tenth-normal standard hydro- 
chloric acid, sufficient to slightly more than neutralize the 
ammonia formed by the digestion. 

To find the suitable number of cc, divide the average per 
cent of protein, as given in the table on page 44, by 0.7. This 
allows for samples containing more than the average amount 
of protein and a reasonable excess. 

Add a few drops of cochineal tincture or some other suitable 
indicator, such as a 0.02 per cent solution of methyl orange. 
Phenolphthalein cannot be used. Dilute to about 60 cc. and 
connect with one of the delivery tubes of the distiUing apparatus 
(Fig. 34), adding water to the receiver if the tube does not dip 
below the surface. 

To the Hquid in the digestion flask add about 250 cc. of 
water, 25 cc. of 4 per cent sodium sulphide solution (to precip- 
itate the mercury from any mercuro-ammonia compounds), 
and shake with a rotatory motion. Continue the shaking and 
add gradually nearly saturated sodium hydroxide to alkaline 
reaction, using Htmus paper as indicator. Usually 30 to 40 cc. 
is sufficient. To avoid bumping add a pinch of coarsely pow- 
dered zinc with particles about the size of those of granulated 
sugar. Without delay attach to the distilling apparatus and 
fight the flame beneath it. When the boifing-point is reached 
watch carefully so that the flame can be instantly turned out 
if there is danger of frothing over. Distill until about 250 cc. of 



70 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 

liquid have passed over, turn off the flame, and disconnect both 
the flask and the receiver tube. Rinse the latter and titrate 
the excess of acid with tenth-normal alkali. Deduct the vol- 
ume of the alkali required in the titration from the volume of 
standard acid previously used and calculate the percentage 
of nitrogen by the factor 0.1401. Multiply the percentage of 
nitrogen by 6.25 to obtain the crude protein. In the case of 
wheat flour the factor 5.70 gives more nearly the true amount 
of protein. 

Standard Acid and Alkali. Although no time is allowed 
in this course for preparing and standardizing solutions, the 
following details are given for the information of the student. 

Hydrochloric acid of half-normal strength, that is contam- 
ing as many grams of HCl per liter as half the molecular weight, 
is first prepared and standardized. This is used directly in 
finding the saponification number of fats and oils (p. 155) 
and, after dilution to tenth-normal strength, in the Kjeldahl 
process and in standardizing tenth-normal sodium hydroxide 
solution. The latter is required not only in the Kjeldahl 
process, but also in the determination of the Reichert-Meissl 
number (p. 157). 

Standard Hydrochloric Acid. The concentrated c. p. acid 
has a specific gravity of 1.20 and contains about 39 per cent 
of the gas; one liter, accordingly, weighs 1200 grams and con- 
tains about 468 grams of HCl. One Hter of half-normal acid 
contains (1.0084-35.46) -^ 2 = 18.234 grams of HCl. Calculated 
from these data, 39 cc. of the concentrated acid diluted to i 
liter will be approximately .half -normal, but it is well to use 
2 or 3 cc. more than the calculated amount, as it is more accu- 
rate to reduce with water to the exact strength, if too strong, 
than to add acid, if too weak. After the approximately half- 
normal acid has been prepared and mixed, determine its strength 
as follows: 

Rinse a burette with a few cc. of the acid and fill to the 
zero mark. Draw off into a beaker with the greatest pos- 
sible accuracy 20 cc. of the acid, dilute to about 150 cc, and 



STANDARD ACID AND ALKALI 71 

add silver nitrate solution drop by drop with stirring until a 
cloudy precipitate of silver chloride no longer forms. Heat 
nearly to boiling, continuing the stirring. After this treatment 
the silver chloride should be in a flocculent form beneath a 
practically clear liquid. Add a drop of silver nitrate to be 
certain that the reagent is in excess. 

Decant the clear liquid onto a weighed Gooch crucible 
prepared as described on page 27. To the silver chloride 
remaining in the beaker add 100 cc. of boiling hot water with 
stirring, then decant onto the crucible as before. Repeat the 
addition of water and decantation twice, transfer the precipitate 
by means of the wash bottle jet to the crucible, clean off the 
last traces from the beaker with a " policeman," and wash 
with five portions of boiling water. Dry the crucible cautiously 
on a piece of asbestos paper, finally raising the heat until the 
silver chloride contracts to small volume and begins to melt 
on the edges. Cool in a desiccator and weigh. 

The weight of HCl equivalent to the weight of AgCl is ob- 
tained by multiplying by 0.2544. This factor is the molecular 
weight of hydrochloric acid (36.468) divided by the molecular 
weight of silver chloride (143.34). The product multiplied 
by 50 gives the weight of HCl per liter (w). The number of cc. 
of water (V) necessary to add to a given volume (v) of the acid 
to reduce it to exactly half-normal strength is found by the 
formula: 

V == v—v 

18.234 

To prepare tenth-normal acid pipette into a graduated Hter 
flask 200 cc. of the half-normal acid, make up to the mark with 
water and shake. 

Standard Sodium Hydroxide Solution. Only a tenth-normal 
solution, that is, one containing 4.C008 grams of NaOH per 
liter, need be prepared. Weigh out quickly somewhat more 
than 4 grams (say 4.5 grams) of dry c.p. sodium hydroxide, 
prepared from the metal, dissolve in 500 cc. of water, and add 



72 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 

barium hydroxide solution sufficient to precipitate any carbonic 
acid present. Filter quickly through a plaited filter into a 
looo-cc. graduated flask. Without washing the filter, make 
up to the mark and shake. Measure out 20 cc. of this solution 
from a burette into a beaker and titrate with tenth-normal 
hydrochloric acid, using a few drops of cochineal tincture as an 
indicator. By proportion calculate the volume of water nec- 
essary to add to a given volume of the solution to make it 
exactly half-normal, that is, so a given number of cc. neutralizes 
the same number of cc. of the tenth-normal acid. 

Gunning-Arnold Modification of the Kjeldahl Method 
Applicable to Black and White Pepper. This method is used 
because the ordinary method does not give the full amount of 
nitrogen present in piperine. To i gram of the material add 
I gram of crystallized copper sulphate, i gram of red oxide of 
mercury, 15 to 18 grams of potassium sulphate, and 25 cc. 
of concentrated nitrogen-free sulphuric acid. Digest at a gentle 
heat with shaking until frothing ceases, then boil for three to 
four hours. In other respects proceed as in the regular Kjeldahl 
method, using, however, 50 instead of 25 cc. of sodium sulphide 
solution. 

Piperine may be calculated from the nitrogen obtained by 
the Gunning-Arnold method in the ether extract from 10 grams 
of the pepper, using the factor 20.36. 

The total nitrogen less that in the ether extract multipHed 
by 6.25 gives the corrected protein. 

Constituents of the Ash of Vegetable Foods. Mayer, as 
an aid to the memory, gives the substances essential for plant 
growth as water, four acids (nitric, carbonic, sulphuric, and 
phosphoric), and four bases (potassium and iron oxides, lime, 
and magnesia). Of these, all but water, nitric acid, and car- 
bonic acid are distinctly inorganic or ash constituents. In 
many fruits and vegetables the bases are partly combined with 
organic acid which burn to carbonates; in cereals and most 
seeds, however, there is sufficient sulphur and phosphorus to 
form sulphates and phosphates with the bases. 



ASH 



73 



Although not essential for growth, chlorine and silica occur 
in many vegetable products and aluminum and some other 
inorganic elements are often present in small amount. 

The ash also contains sand and other extraneous dirt which 
become attached to the plant during growth or handling. 
So-called pure ash is ash corrected for sand, carbon dioxide, 
and unburned carbon or charcoal. 

•^^Determination of Ash. Weigh 2 grams of the material 
on a watch-glass and place in a weighed porcelain crucible, wide 
form, 40 mm. in diameter. Bulky material may be added in 
several portions during the incineration. 

If a small platinum dish or crucible is at hand it will be 
found by far the best for 
ash determination, but the 
expense is prohibitive if it 
is to be used only for this 
course. 

Heat gradually on a piece 
of asbestos paper to dull 
redness and continue to heat 
at that temperature until 
further heating does not ap- 
pear to reduce the bulk of 
the residue or change its 
appearance. The ashing is 
best finished in a muffle 
furnace, preferably of the 
electric type (Fig. 37), but 
lacking this, may be carried out on the asbestos paper, using a 
second piece to cover the crucible and thus raise the heat to 
uniform dull redness. If diflSculty in securing a white or light 
gray ash is experienced, remove from the furnace, cool, add i or 
2 cc. of water, evaporate to dryness, and again ignite. By this 
treatment particles of carbon will be liberated from any salts 
which may have become fused about them and thus rendered 
more readily combustible. Overheating retards rather than 




Fig. 37. — Hoskins Electric Furnace. 



74 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 

hastens the burning, furthermore at a bright red heat alkali 
chlorides are volatilized and carbon dioxide is expelled from 
calcium carbonate. Finally cool in a desiccator and weigh. 

^ Nitrogen-free Extract. The constituents of vegetable sub- 
stances, other than those of the five groups which we have learned 
to determine, are known collectively as the nitrogen-free extract. 
The most important substances of the group are the carbohy- 
drates, including starch, sugars, and gums. Other substances 
which, if present, belong in this group are organic acids, tannin 
substances, and various minor constituents. 

The percentage of nitrogen-free extract is obtained by dif- 
ference, that is, the sum of the percentages of water, ether extract, 
crude fiber, crude protein, and crude ash is subtracted from loo. 

In the case of the cereals and some other starchy products, 
the results obtained represent fairly accurately the amount of 
starch and related carbohydrates present; in some other cases 
they have less definite significance. 

Chemical Properties of Starch. The formula CeHioOs, 
ascribed by the earlier chemists to starch, represents the ratio 
of the atoms of the three elements in the molecule rather than 
the actual molecular constitution. It is now considered that 
the molecular weight of starch, as well as of Dextrin and Cellu- 
lose, which also contain the three elements in the ratio of 6 : lo : 5, 
is, like the molecular weight of the proteins, very large, the hypo- 
thetical formula of starch being given as (C6Hio05)2oo and of 
dextrin as (C6Hio05)4o- However great may be the scientific 
importance of determining the exact molecular constitution, the 
simple formula CeHioOs, which represents a molecular weight 
exactly to of that of Dextrose (C6H12O6), suffices for analytical 
purposes. 

Starch is the most important carbohydrate occurring in the 
vegetable cell. It is the first visible product of photosynthesis 
whereby the carbon dioxide of the air and the water drawn up 
through the roots are combined in the leaf, by the action of 
sunlight and through the agency of the Chlorophyl. As fast 
as it is formed in the leaf it is redissolved and moved to other 



STARCH IN WHEAT FLOUR 75 

parts of the plant. In many seeds, roots, tubers, and barks it is 
deposited as reserve material in the form of granules the micro- 
scopic characters of which are considered in Chapter V. 

Starch is dissolved by the enzymes of malt {Diastase), 
saliva (Ptyalin) and pancreas (Pancreatin) , with the formation 
of Maltose. Heated with dilute acids other carbohydrates 
(soluble starch, amylodextrin, erythrodextrin, achroodextrin, 
maltodextrin) , are believed to be formed successively, the blue 
color with iodine changing gradually to red and the red color in 
turn becoming more and more faint and finally disappearing 
entirely. The final product of this acid conversion is dextrose, 
and on this principle are based the common analytical processes. 
The Pentosans and to some extent the Cellulose of the cell walls 
are also converted into dextrose on heating with dilute acid, 
hence if considerable amounts of these are present the starch 
must first be dissolved out by malt extract (diastase), sahva, or 
some other solvent which acts only on the starch. In the so- 
called diastase method malt extract is employed. The dextrose 
obtained by the acid conversion whether by direct treatment or 
after digestion with malt extract is best determined by copper 
reduction, employing a boiling alkaline solution of copper sul- 
phate and Rochelle salts, known as Fehling solution. Dextrose, 
levulose, maltose, and lactose reduce in different degrees the 
copper of this solution to copper suboxide (CU2O), whereas 
sucrose and the dextrins are practically non-reducing. 

^ Determination of Starch in Wheat Flour. The diastase 
method, involving, as it does, not only the preliminary treatment 
with malt extract, but also the determination of the correction 
due to the soluble carbohydrates in the malt extract, is too 
difficult for the beginner. Fortunately ordinary wheat flour 
contains so little cellulose and pentosans that direct treatment 
with acid by Sachsse's method ^ introduces no appreciable error. 
Soluble carbohydrates are present only in small amount so that 
preliminary washing with water or dilute alcohol to remove 
these may be omitted. Proceed in duplicate as follows: 

' Chem. Centralbl., 1877, p. 732. 



76 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 

Method. Weigh out 2.5 grams of wheat flour on a watch- 
glass, transfer to a flask of about 500-cc. capacity, add 200 cc. 
of water and 20 cc. of 25 per cent hydrochloric acid (sp.gr. 
1. 1 2 5), and rotate the flask until the flour is evenly distributed 
and there are no lumps on the bottom. Heat to boiling and boil 
very gently for two hours, replacing, from time to time, any water 
lost by evaporation, if perceptible. While the solutions are 
boiling pack two porcelain Gooch crucibles with an asbestos felt 
\ in. thick, wash thoroughly with water to remove fine particles 
of asbestos, then with alcohol and with ether, dry thirty minutes 
in a boiling water oven, cool in a desiccator, and weigh. 

The asbestos (amphibole), which must be of the grade spe- 
cially furnished by dealers for copper reduction work, is prepared 
in advance for the use of the class. It is first digested with i : 3 
hydrochloric acid for two or three days and washed free of acid. 
It is then treated for a similar period with caustic soda solution 
and for a few hours with hot Fehling solution. After washing 
free of alkah it is digested with nitric acid for several hours and 
washed free of acid. A quantity of the pulp is shaken with 
water and the crucible loaded while it is in suspension. 

On the day following the digestion of the flour with acid add 
a few drops of phenolphthalein solution and 20 per cent sodium 
hydroxide solution to slight alkaline reaction as shown b}'' the 
pink color. Add hydrochloric acid, drop by drop, until the 
pink color just disappears and make up to 500 cc. in a grad- 
uated flask. Shake and filter through a dry paper into a dry 
flask. 

Determine dextrose by the Munson and Walker method ^ 
as follows: 

Pipette into a 400-cc. beaker 25 cc. of copper solution (34.639 
grams c. p. crystals of copper sulphate dissolved in water and 
diluted to 500 cc), 25 cc. of alkaline tartrate solution (173 grams 
of c. p. crystallized Rochelle salts and 50 grams of sodium hydrox- 
ide dissolved in water and diluted to 500 cc), and 50 cc. of the 
filtered flour extract. Cover with a watch-glass, heat on an 

^ Jour. Amer. Chem. Soc, 1906, 28, p. 163. 



PENTOSANS IN MILL PRODUCTS 77 

asbestos gauze over a Bunsen burner with the flame so regulated 
that boihng begins in four minutes, and boil for exactly two 
minutes. Filter at once on one of the weighed Gooch crucibles, 
using suction. Transfer the cuprous oxide to the crucible and 
wash thoroughly with water at 60° C, then wash with 10 cc. 
of alcohol, and finally with 10 cc. of ether. Dry thirty minutes 
in a boihng water oven, cool in a desiccator, and weigh. In 
Munson and Walker's table (pp. 213-221), find the amount of 
dextrose corresponding to the weight of copper suboxide ob- 
tained, multiply this weight by .9 to convert into the weight of 
starch, divide by .25 (the weight of flour corresponding to 50 cc. 
of the solution or yV of the total amount weighed out), and 
multiply by 100, thus obtaining the percentage of starch. 

Pentosans in Mill Products. These substances {xylan, araban, 
etc.), bear the same relation to the pentose sugars {xylose, ara- 
binose, etc.) as starch does to dextrose. Thanks to the re- 
searches of Tollens, Krober, and others, they may be deter- 
mined by conversion into furfural by distillation with hydrochloric 
acid and precipitation of the furfural as phloroglucide by phloro- 
glucinol. 

Flour Testing and Analysis. Through the efforts of Snyder 
and others, the work of the flour laboratory has become of great 
practical importance. In addition to the constituents already 
considered in this chapter, determinations are made of Gluten 
(wet and dry), Acidity, Absorption (water-absorbing power), 
and other physical characters. Of special value are scientific 
Baking Tests, involving the volume, flavor, texture, and color 
of the loaf. 

Bleaching of flour with nitrogen peroxide is detected by 
quantitative determinations of Nitrites, and Gasoline Color Value 
(the color extracted by gasoline) and bleaching with chlorine is 
detected by estimation of the Chlorine in the Fat, Iodine Number 
of the Fat, and the gasoline color value. 



78 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 

Yeast and Baking Powder 

Function of Aerating Agents. Yeast and baking powder 
are useful merely to generate carbon dioxide. The gas in its 
efforts to escape converts the dough, which otherwise would 
remain a soggy mass, into a light and porous loaf. Like ex- 
tracts, spices, tea, and coffee, they have practically no food value. 

In yeast leavening the alcohol, which, together with the 
carbon dioxide gas, is formed from the sugars, is either driven 
off in baking or else remains behind in such small quantities as 
to be negligible; in leavening by baking powder, however, the 
by-products of the reaction are appreciable quantities of fixed 
salts with more or less marked physiological action. 

Yeast whether dry or compressed consists of an organism, 
one of several varieties of the species Saccharomyces cerevisicB, 
mixed usually with an inert material such as starch, or meal. 
The best variety for bread-making is top yeast (Fig. 98), 
obtained from distilleries. Top yeast is also used in ale brewing. 
Bottom yeast (Fig. 97), such as is used in lager beer brewing, is 
considered inferior for bread-making. The plant belongs to the 
unicellular fungae and reproduces by budding. 

The aerating value of yeast is tested by the amount of car- 
bon dioxide evolved from a sugar solution to which a certain 
weight of the sample has been added. Living yeast cells are 
distinguished from the dead cells by mounting in a very dilute 
solution of fuchsin or some other coal-tar color and microscopic 
examination. The live cells are not stained, whereas the dead 
cells absorb the dye and are readily distinguished from the 
others by their color. 

The chemical reactions involved in fermentation are consid- 
ered on page 168. 

Baking Powder consists of a dry mixture of sodium bicar- 
bonate with tartaric acid, potassium bitartrate (cream of tar- 
tar), calcium acid phosphate, sodium aluminum sulphate (soda 
alum), or aluminum sulphate. Starch is usually present to 
prevent deterioration. 



BAKING POWDER 79 

The reactions involved and the fixed products remaining in 
the bread will be understood from the following equations: 

(1) H2C4H406 + 2NaHC03=Na2C4H406,2H20 + 2C02 

Tartaric acid Sodium Sodium tartrate Carbon 

bicarbonate dioxide 

(2) KHC4H406+NaHC03 = KNaC4H406+C02+H20 

Potassium Sodium Potassium sodium Carbon Water 

bitartrate bicarbonate tartrate dioxide 

(3) CaH4(P04)2 + 2NaHC03 

Calcium acid Sodium 

phosphate bicarbonate 

= CaHP04 + Na2HP04 + 2CO2 + 2H2O 

Calcium Disodium Carbon Water 

monohydrogen hydrogen dioxide 

phosphate phosphate 

(4) Na2Al2(S04)4+6NaHC03 = Al2(OH)6+4Na2S04+6C02 

Sodium aluminum Sodium Aluminum Sodium Carbon- 

sulphate bicarbonate hydroxide sulphate dioxide 

(5) Al2(S04)3+6NaHC03 = Al2(OH)6+3Na2S04+6C02 

Aluminum Sodium Aluminum Sodium Carbon 

sulphate bicarbonate hydroxide sulphate dioxide 

There can be no doubt as to the value of baking powder 
in yielding a light, easily masticated loaf, but how far this is offset 
by the physiological action of the residual products of the 
reaction opinions differ. Of the residual products, sodium 
tartrate, potassium sodium tartrate (Rochelle salts), disodium 
hydrogen phosphate, and sodium sulphate (Glauber's salts) are 
cathartics well known in medicine. The quantities ordinarily 
eaten in baking powder bread or in cake are much less than the 
medicinal doses. 

■^Material for Laboratory Practice. Three baking powders, 
one of the cream of tartar type (Royal, Cleveland's, Price's, etc.), 
one of the phosphate type (Horsford's), and one of the alum or 
alum-phosphate type (K. C, Calumet, etc.), should be pro- 
vided for qualitative tests, which will require but a short time. 

Quantitative determinations require no little time and 
skill, and need not be attempted. Of special importance are 
estimations of total and available carbon dioxide, that is, the 
amount of gas Hberated by acid and water respectively. In 



80 NATURAL VEGETABLE FOODS AND MILL PRODUCTS 

both cases the carbon dioxide, freed from water by first passing 
through an inverted condenser and then through a tube con- 
taining calcium chloride, is absorbed either in a " potash bulb " 
containing caustic alkah, or else in a U-tube containing a fused 
mixture of sodium hydroxide and calcium oxide, known as 
soda-lime. 

■^Test for Sulphates. Boil about i gram of the powder in a 
beaker with loo cc. of water and 3 cc. of concentrated hydro- 
chloric acid until a nearly clear solution is obtained. To a 
portion of the liquid in a test-tube add a few drops of barium 
chloride solution. If a copious precipitate forms, the powder 
contains alum, aluminum sulphate or else calcium sulphate filler. 

*Test for Phosphates. To another portion of the solution 
obtained as described in the preceding paragraph, while still 
hot, add ammonium molybdate solution. The formation of a 
bright yellow precipitate of ammonio-phosphomolybdate shows 
the presence of acid phosphate. If neither sulphates nor phos- 
phates are present the powder may be assumed to belong to 
the tartaric acid or cream of tartar class, the two being closely 
related. 

^Leach Test for Aluminum Salts. This test ^ depends on 
following reaction: 

Na2Al204 + 2NH4Cl+4H20 = Al2(OH)6+2NH40H+2NaCl. 

Sodium Ammonium Aluminum Ammonium Sodium 

aluminate chloride hydroxide hydroxide chloride 

Burn about 2 grams of the powder in a platinum dish at a 
dull red heat. It is not necessary to secure a white ash, as a 
small amount of unburned carbon does not interfere with the 
test. Extract with boiling water and filter. Add to the filtrate 
sufficient ammonium chloride solution to produce a distinct odor 
of ammonia. A flocculent precipitate indicates aluminum. 

If calcium phosphate is present in the ash it will be insoluble 
in water ; sodium or potassium phosphate, if present, will go into 

^ Mass. State Board of Health, 31st Ann. Rep., 1899, p. 638. Leach's " Food 
Inspection and Analysis," Third ed., p. 343. 



BAKING POWDER 81 

solution, but the phosphoric acid will only precipitate when an 
aluminum salt is present. 

If the student is not provided with a platinum dish, this 
test may be performed in his presence by the instructor or may 
be omitted. 

*Test for Starch. Add a solution of iodine in potassium 
iodide to the dry powder or the pasty liquid obtained by boiling 
with water. The characteristic blue color indicates starch. 
The variety of starch may be identified under the microscope. 



CHAPTER V 
MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 

Introduction 

Province of Microscopic Examination. The methods for 
the determination of the six groups of constituents of ground 
vegetable substances, detailed in Chapter IV, although very 
important in measuring the food value of the substances and 
in forming an opinion as to their purity, are of no decisive value 
in identifying unknown substances either singly or in mixtures. 
By these methods the analysis of different cereal products and 
various mixtures often shows practically the same composition, 
and the same is true of a variety of oil-seed products and other 
vegetable substances. Determination of starch, although serv- 
ing to distinguish starchy from non-starchy products and those 
with high starch content from those with a low percentage, 
throws no light on the source of the starch. 

A study of the histological structure, commonly known as 
microscopic examination, on the other hand, furnishes decisive 
information as to the nature and source of the constituents of 
vegetable products, thus supplementing the chemical analysis. 
Each cereal, oil seed, spice, and fruit, as well as each weed seed 
and common vegetable adulterant, has definite microscopic 
characters which permit in almost every instance its identifica- 
tion in the finest powders. 

While some experience in the use of the compound micro- 
scope and an elementary knowledge of vegetable histology are 
desirable, it has been the author's experience that a careful 
student in eight exercises can gain an insight into the subject 
sufficient to enable him to prosecute intelligently further studies. 

83 



84 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 



Microscopical examination is also of great importance in the 
examination of drugs, textile fibers, paper, and other technical 
products and, as in the case of foods, should be carried on in 
conjunction with chemical analysis. 

Histological work is distinctly botanical and should not be 
confused with chemical microscopy or microchemical analysis, 
which is a branch of qualitative analysis based on the reactions 
observed under the microscope. The student wishing to pur- 
sue this subject is referred to Chamot's Chemical Microscopy. 
Construction of the Microscope. The optics and detailed 

construction of the microscope, 
as of the polariscope, is a special 
subject for which the student 
or even the skilled microscopist 
has little need. Only a brief 
description of the instrument 
such as seems essential for prac- 
tical work is here given. 

Fig. 38 shows a simple form 
of compound microscope suited 
for the examination of food 
products. The stage S carries 
the slide or glass slip on which 
the material is mounted. The 
magnifying parts are (i) the 
objective 0, of which two are 
shown in the figure mounted on 
a double nosepiece, a device for 
instantly throwing one objective 
into service and the other out, 
thus changing the magnification, 
and (2) the eyepiece or ocular 
E, consisting of lenses mounted 
in a metal cylinder which is introduced in the top of the tube 
T of the microscope. C is the coarse and F the fine adjust- 
ment for focusing on the mount. The mirror M is mounted 




Fig. 38. — Microscope for Food 
Examination. 



MICROSCOPE AND ACCESSORIES 



85 



below a hole in the stage on swinging supports so that it can be 
adjusted to cast a bright light on the material under examina- 
tion, which otherwise, when magnified, would be too dark to 
show its structure. The light is tempered by different size holes 
or by a so-called iris diaphragm. For some kinds of work a 
substage condenser mounted above the mirror is essential. 
Eyepieces of different powers are also provided. 

Microscopic Accessories. Micrometer. Each microscope 
should be provided with an eyepiece micrometer consisting of a 

scale ruled on a glass disc mounted 
in a special eyepiece. This is used 
for measuring starch grains and 
other minute objects. 

Polarizing Apparatus. In addi- 
tion to the microscopes for the 
use of the individual students one 
equipped with polarizing apparatus 
should be provided for the class. In 





Fig. 39. Fig. 40. 

Fig. 39. — Chamot Polarizing Microscope. PO polarizer; PA analyzer. 
Fig. 40. — Dropping Bottle for Microscopic Reagents. 



the polarizing microscope one of the Nicol prisms (the polarizer), 
is mounted below the stage and the other (the analyzer) in the 
microscope tube or above the eyepiece. One or the other of 



86 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 

these is in a revolving mount so that the axes of the two can 
be crossed as in the saccharimeter. Fig. 39 shows the Chamot 
polarizing microscope specially designed for microchemical 
analysis, but well suited for the examination of starch grains 
with polarized light. By adding a double nosepiece and a 
device for swinging the polarizer out of the axis, when ordinary 
illumination is desired, this same microscope can be used in 
food examination, thus avoiding the duplication of instruments 
for courses in chemical microscopy and food analysis. 

Slides. Slips of glass, 3X1 in., for mounting materials for 
observation. 

Cover Glasses. Circles of very thin glass f in. in diameter. 

Dropping Bottles (Fig. 40) for 5 per cent sodium hydroxide 
solution and iodine in potassium iodide solution (0.05 gram iodine, 
0.2 gram potassium iodide, 15 cc. water). 

^Calibration of Micrometer. The student should calibrate 
his eyepiece micrometer partly to gain experience in finding an 
object under the microscope and in focusing and partly for a 
clearer understanding of the nature and use of the micrometer 
scale. The scale is usually graduated in millimeters and tenths 
of a millimeter, but this has no significance, as the material under 
examination and the scale are magnified to different degrees, 
and the magnification of the material differs with the objective. 
For the cahbration a stage micrometer is used. This consists 
of a sHde on which is etched an accurate scale with ultimate 
divisions 0.0 1 mm. apart. 

Set the microscope in front of a north window or at least 
where it will not be in direct sunlight. Place the stage microm- 
eter on the microscope stage, and introduce the eyepiece 
micrometer in the tube of the instrument. 

Draw out the microscope tube to standard length (usually 
160 mm.). Using the low-power objective and eyepiece microm- 
eter find the scale on the stage micrometer with the aid of the 
concentric circles which surround it, then, by moving the stage 
micrometer and turning the eyepiece micrometer, superimpose 
one scale on the other and count the number of ultimate divisions 



MOUNTING 87 

on the eyepiece scale corresponding to a certain number of ulti- 
mate divisions or hundredths of a millimeter on the stage scale. 
Divide the second figure (expressed as a decimal of a millimeter) 
by the first thus obtaining the value of each ultimate division 
on the eyepiece scale. Repeat the operation, using the other 
objective. To eliminate cumbersome decimals the micron or 
thousandth of a millimeter, represented by the Greek letter fx, 
is commonly used in place of decimals of a millimeter. 

Examples. If 50 divisions on the eyepiece scale correspond 
to 80 divisions or 0.8 mm. on the stage scale, using a low- 

0.8 
power objective, then each division of the former equals — 

or 0.016 mm. or 16 m. If 74 divisions on the eyepiece scale 



Fig. 41. — Microscopic Slide with Mount. 

correspond to 20 divisions or 0.2 mm. on the stage scale, using 

a high-power objective, then each division of the former equals 

0.2 

— or 0.0027 mm. or 2.7 u. 

74 

In measuring an object all that is necessary is to count 
the number of ultimate divisions of the eyepiece scale and 
convert into microns, using the proper factor for the objective. 

Mounting. First place a drop of water on a slide, which is 
conveniently accomplished by dipping the finger in water and 
touching it to the slide. Introduce into the drop from the end 
of a penknife blade a small quantity of the material which, if 
a powder, should about equal in bulk a grain of mustard seed, 
and place over it a cover glass (Fig. 41). By moving the cover 
glass backward and forward the material can be evenly dis- 
tributed through the Uquid. The material is first examined in 



88 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 

the water mount thus prepared and, if desired, again after 
treatment with a reagent such as iodine solution to stain the 
starch grains or sodium hydroxide solution to dissolve the 
starch and proteins and clear the tissues. 

Permanent mounts are not necessary for the work outlined 
in this chapter. The medium used for permanent mounts is 
usually Canada balsam, glycerine jelly, or glycerine, the cover 
glass in the latter case being fastened to the slide by a ring of 
cement. 

Observation of the Mount. Adjust the mirror until the 
field is well illumined. Place the mount on the stage so that 
the material is over the middle of the hole. With the shorter 
or low-power objective in position, lower the tube carefully by 
the coarse adjustment until it nearly touches the cover glass, 
then, looking through the eyepiece, raise the tube until some part 
of the material or else a scratch on the glass comes into focus. 
Examine first with the low-, then with the high-power objective, 
taking care not to hit the cover glass. Move the slide with 
the left hand to bring different parts of the mount in the field 
and focus with the right hand. As a new focus must be found 
for each change in position of the slide and for parts of the 
mount at different depths in the same position, the fingers on 
the fine adjustment are kept continually busy. If the field is 
too light, use a smaller hole in the diaphragm; if too dark, use 
a larger one. Although theoretically more light should be used 
for the high- than the lower-power objective, after a few trials 
a degree of illumination can be found which will answer for both 
powers, and the attention can be confined to the details of 
moving the slide, focusing, and observation. 

Microscopy of Starches 

Nature of Starch Grains. Starch occurs widely distributed 
in the vegetable kingdom as reserve material in the form of 
minute grains or granules. In seeds the starch is laid up as 
food for the plants' progeny — the young plant — to be used while 
it is reaching up through the soil and before it forms chlorophyl 



STARCHES 



89 



in its leaves and thus is able to manufacture its own carbona- 
ceous food from carbon dioxide 
and water. In roots, root 
stalks, tubers, and barks the 
starch serves the needs of the 
plant itself during the follow- 
ing growing season. Certain 
immature fruits, such as ba- 
nanas and apples, also contain 
starch grains, but as these dis- 
appear on ripening, being con- 
verted into sugars or other 
soluble carbohydrates and in 
neither case nourish the plant 
or its progeny, the starch can 
hardly be classed as reserve 
material. 

The shape, size, and other characters of the starch grains 




Fig. 42. — Starch Grains Viewed with 
Polarized Light. / potato; II cur- 
cuma; /// wheat; IV bean. X300. 

(WiNTON.) 




Fig. 43. — Wheat Starch. X300. (Moeller.) 

differ greatly in different species, but are remarkably constant 
for the same species and organ. Many times in identifying an 



90 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 

unknown material the microscopist must depend largely or 
entirely on the characters of the starch grains, and in most cases 
these characters are decisive. 

Form. The commonest forms are (i) globular (peanut, some 




Fig. 44. — Oat Starch. X300. (Moeller.) 




Fig. 45.— Com Starch. X300. (Moeller.) 
grains of maize), (2) lenticular or lens-shaped (large grains of 
wheat, rye, and barley), (3) ellipsoidal (legumes), (4) ovoid or 
pear shaped (potato, Bermuda arrowroot, yam, banana), (5) 
polygonal (most grains of maize, oats, and rice; small grains of 
wheat, rye, and barley), (6) truncated or kettle-drum shaped 
(cassava) . 



STARCHES 



91 



Size. The grains range from less than i^ (cockle) to over 
130/i (canna). Sometimes large and small grains occur in the 




Fig. 46. — Lentil Starch. X300. (Moeller.) 




Fig. 47.— Potato Starch. X3C0. (JNIoeller.) 

same product with no intermediate sizes (wheat, rye, and 
barley) . 

The Hihim is the organic center of the grain. It is con- 
spicuous in some grains (maize, legumes), scarcely evident in 



92 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 

others (wheat, rye, barley). It is located in the geometric 

center of round and polygonal grains, in one end of ovoid grains. 

In legumes it is elongated. 

Rings. In some grains rings, concentric about the hilum, 

are distinct, in others scarcely evident. 

Aggregates. The grains in certain products are often united 

to form aggregates of a few (cassava) or numerous individuals 

(rice, oats, buckwheat). 

Polarization Crosses are more or less evident with crossed 

Nicol prisms (Fig. 42). Except for the crosses the grains stand 

out brilliantly white, contrasting strongly with the dark field. 

Because of these phenomena the 
grains are considered to be 
sphero-crystals. 

^Examination of Typical 
Starches. The following starches 
should be examined: Wheat, oat, 
bean, corn (maize), potato, and 
cassava (tapioca) . Material suit- 
able for the examination of the 
first three is obtained by cutting 
open wheat and oat kernels and 

Fig. 48. — Cassava Starch. X300. 

(MoELLER.) ordmary white or navy beans, 

and scraping out a portion of 

the powdery interior. Corn starch is sold in every grocery 

store. Potato and cassava starch are obtainable from dealers 

in chemical supplies, although uncooked potatoes and dried 

cassava roots answer the purpose quite as well. 

A single laboratory period is sufficient for the study of 
these six forms of starch grains. Some of them will be seen 
again in the examination of various vegetable foods. 

Mount in water and, using first the low- and then the high- 
power objective, note the shape of the grains, the character of 
the hilum (if visible), whether or not rings are evident, and the 
presence or absence of aggregates. Next, using the eyepiece 
micrometer, measure the diameter or length of the largest grain 





^ ¥' 


-W 


^-■f 






^^ 


tr^ ^ 


^ ^ '■ 


>!) 


^ \^ 


. n 


2> 



TYPICAL FOODS 



93 



found. Finally, with the polarization microscope observe the 
distinctness of the crosses and their place of intersection. 

To study the action of iodine on the grains place a drop of 
the reagent on one side of the mount and draw it under the 
cover glass by means of a piece of filter paper held on the 
opposite side so as to suck out a portion of the water. 

The chief characters are shown in figures 43 to 48, inclusive, 
or are given in the following table: 





Wheat 


Oat 


Bean 


Maize 


Potato 


Cassava 


Form 


Lenticular 


Polygonal 


Elliptical 
or Bean- 
shaped 


Polygonal 


Pear- 
shaped 


Truncated 


Maximum 
Size 


50M 


lOfl 


60/X 


35m 


ICO/U 


35m 


Hilum 


Central, 
small 


Central, 
small 


Elongated, 
large 


Central, 
large 


Eccentric 
in small 
end of 
grain 


Central, 
distinct 


Rings 


None or in- 
distinct 


None or in- 
distinct 


Distinct 


None or in- 
distinct 


Distinct 


Indistinct 


Aggre- 
gates 


None 


Numerous, 
up to 100 
grains 


None 


None 


None 


Present, 
mostly 2 to 
3 grains 


Polariza- 
tion 
Crosses 


Indistinct 


Distinct 


Distinct 


Distinct 


Distinct 


Distinct 



Microscopy of Typical Foods 

^Materials for Laboratory Practice. The following unground 
crude products should be provided: Wheat, rye, corn (maize), 
oats, buckwheat, peas, cotton seed, linseed (flax seed), black 
pepper, cayenne pepper, cinnamon (cassia) bark, ginger root, 
coffee beans, cocoa beans, and tea; also the following ground 
products for use in practice mixtures: Wheat flour, ground wheat 



94 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 

bran, ground rye bran, corn (maize) meal, ground oatmeal, buck- 
wheat flour, ground peas, cotton seed meal, linseed meal, ground 
black pepper, ground cayenne pepper, ground cinnamon, ground 
ginger, ground coffee, and cocoa. All of the ground products 
should be fine enough to pass at least a i mm. (2V in.) sieve. 
Naturally the three kinds of flour and the cocoa will be impal- 
pable powders. 

Six laboratory periods should be given up to studying 
the general structure of the crude products. After this prac- 
tice a day may be devoted to the identification of the ground 
products, both singly and in mixtures, submitted by the in- 
structor. 

■^Wheat. All of the true cereals are dry, one-seeded fruits 





Fig. 49. — Wheat. Grain in Longitudinal Section and Entire. X8. (Schumann.) 

consisting largely of the starchy seed, the fruit coat or Pericarp 
being represented only by the outer bran layers. If a wheat 
kernel is examined with the naked eye it will be seen that on 
one side is a deep cleft extending the entire length of the kernel 
while on the other side at the base is a depression marking the 
location of the embryo or germ beneath. At the apex is a beard 
of fine hairs visible under a lens. 

If a kernel is cut with a penknife into halves, through the 
cleft (Fig. 49), it will be seen from an examination of the 
cut surface with the naked eye, that the hard mass within the 
bran coats consists in large part of the Endosperm which, 
tested with a drop of iodine in potassium iodide solution, turns 
deep blue, showing that it is rich in starch. This starch is reserve 



WHEAT 



95 



food for the plantlet while beneath the soil. White flour is 
made from the endosperm. The Embryo {e) does not contain 
starch, but is rich in oil and proteins, the latter being different 
from the gluten of the endosperm. It consists of a minute 
plantlet with a cluster of leaves above, a radicle or embryo root 
below and, at the side next to the endosperm, a kind of sucker 
{Scutellum) for drinking in the sugar solution formed by the 
action of the enzyme diastase on the starch during germination. 
These details of structure will not, perhaps, be evident in the 







Fig. 50. — Wheat. Cross section through bran coats and outer endosperm. F 
pericarp consists of cut cuticle, epi epicarp, hy hypoderm, tr cross cells, and 
tu tube cells; S spermoderm consists of two brown layers; P perisperm; 
5 endosperm consists of al aleurone cells and am starch cells. X160. 

(MOELLER-TSCHIRCH.) 

student's section, but he will note the absence of starch as 
demonstrated by the iodine test. 

Histology. Fig. 50 shows the outer part of a cross section 
through the center of a wheat kernel magnified 160 diameters. 
Such a section is cut with a plano-concave razor or a mechanical 
section-cutter known as a microtome, after softening the kernel 
by soaking in water. As it requires considerable practice to 
secure good cross sections of grains and seeds, the student in the 
limited time allowed for this course should depend either on 
permanent mounts or else on the illustrations. 



96 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 



F is the fruit coat or Pericarp, consisting of three layers, not 
including the cuticle which is not cellular; S is the seed coat or 
Spermoderm, corresponding to the skin of an almond or bean; 




..--r^^ £ 



P is the Perisperm or remains of the body of the ovule ; E is the 
Endosperm, consisting of Aleurone Cells [al) and Starch Cells 
{am). 

While cross sections are of great value for a scientific study 
of a vegetable product, especially in deciding as to the number 



WHEAT 97 

and arrangement of the layers, they are neither so Interesting 
nor so valuable in identification as surface preparations, that is, 
the layers removed by scraping the kernel, previously soaked 
for a time in water, with a penknife. In ground products cross 
sections are seldom found, the layers being largely in surface 
sections and, therefore, are seen through the microscope in 
surface view. Fig. 51 shows the successive layers of the wheat 
kernel in surface view, although not all of these are readily 
found or are of value in identification. The student should find 
all the important layers in water mounts of his own prepara- 
tion. 

The outer layer (Epicarp) consists for the most part of 




Fig. 52. — Wheat. Surface view of cross cells. X300. (K. B. Winton.) 

elongated, distinctly beaded cells, so arranged as to " break 
joints" (Fig. 51 epi); at the apex of the kernel, however, the 
cells are polygonal and from among them arise the hairs of the 
beard. The Hairs (t) are broad at the base, pointed at the end, 
and have a distinct cavity the breadth of which is less than the 
thickness of the walls. They seldom, if ever, exceed looo/x in 
length. A second and often a third layer of elongated cells, 
practically the same as those of the epicarp, are also present. 
The next layer (ir) consists of Cross Cells, so-called because they 
cross those of the preceding layers at right angles. Fig. 52 
shows a group of cross cells more highly magnified. The cross 
cells are highly characteristic because they are arranged side 
by side in rows and, therefore, do not break joints. It should 
also be noted that both the thick side walls and the thin end 



98 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 

walls of the cells are distinctly beaded, whereas in rye the 
side walls are indistinctly beaded and the end walls are often 
swollen. 

The curious cells of the Intermediate Layer {in) are not 
likely to be encountered and would not be mentioned were it 
not that the beginner often runs across the imusual. The 
Tube Cells (tu) which occur in all the cereals are remarkable in 
that they do not form a continuous layer, but occur isolated or 
only here and there in contact with one another. Such a forma- 
tion is known as Spongy Parenchyma, and the spaces between 
such cells as Intercellular Spaces. In cross section (Fig. 50 tu), 
the tube cells appear as rings. 

All the layers thus far enumerated, together forming a thin 
skin, make up the fruit coat or Pericarp corresponding to the 
flesh and stone (excluding the kernel) of the peach or the pod 
of the pea. None of the cells contains visible contents. 

The two crossing layers of the seed coat or Spermoderm 
(Fig. 51, i and 0), are still thinner, the cell walls appearing like 
mere lines. Were it not for their brown color they would be 
hardly noticeable. The Perisperm (P), is not evident without 
special treatment. 

The Aleurone Cells [at) forming the outer layer of the endo- 
sperm, although conspicuous because of their thick walls and 
abundant contents of proteins and fat, are of little value in 
identification, as they occur in all the cereals and some other 
grains. 

By far the greater part of the kernel consists of the thin- 
walled Starch Cells, also known as flour cells. These contain the 
Starch Grains {am), which we have already studied (p. 89, Fig. 43), 
imbedded in two proteins, Gliadin and Glutinin. These latter 
form with water Gluten, which gives wheat flour its peculiar 
dough-making properties and contributes so markedly to its 
nutritive value. The gluten, being a colloid, is not visible in a 
water mount except on special treatment. 

The large lenticular starch grains are characteristic not of 
wheat alone, but of the group wheat, rye, and barley. The 



RYE 99 

experienced microscopist can distinguish the three from one 
another by the size of these grains. In rye the grains often 
exceed 50M in diameter, in wheat they practically never reach 
50/X, while in barley they seldom exceed 35/1. 

Characteristic Elements, (i) The hairs (Fig. 51, /; Fig. 54, T), 
distinguished with difficulty from rye hairs but readily from oat 
hairs (Fig. 54, A), by their shorter length (less than looo/x) and 
broad base; (2) the cross cells (Fig. 52), distinguished from rye 
cross cells (Fig. 53), by their more distinct beads and their thin 
beaded (not swollen) end walls; (3) the large lenticular starch 



Fig. 53. — Rye. Surface view of cross cells. X300. (Winton.) 

grains (Fig. 43), not exceeding 50/x (distinction from rye), but 
often exceeding 35/^ (distinction from barley). 

■*"Rye. The structure is throughout analogous to that of 
wheat. Study the layers noting the distinctions given in the 
foregoing paragraph. The difference in the Cross Cells (Figs. 
52 and 53) serves to distinguish rye bran and other products 
containing the bran from the corresponding products of wheat. 
The difference in the size of the starch grains and the difference 
in the fragments of cross cells, obtained by special treatment to 
remove the starch, enable a skilled microscopist to distinguish 
rye flour from wheat flour. A more certain and often the only 
ready means of distinction is the following test: 

Bamihl Test. This test, as modified by the author, consists 



100 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 



A 



n 



r\ 



Fig. 54. — Hairs from wheat (T) 
and Oats (J). Xi6o. (Winton.) 



in mounting 1.5 milligrams of the 
flour in a drop of water containing 
in each liter 0.2 gram of water- 
soluble eosin. Before releasing the 
cover glass move it back and forth 
over, the liquid, taking care that 
none of the flour escapes from be- 
neath it. By this treatment the 
gluten of wheat flour and of a mix- 
ture containing a considerable part 
of wheat flour forms into rolls which 
greedily absorb the red dye and are 
readily seen with the naked eye. 
Rye flour, since it contains no 
appreciable amount of gluten, does 
not yield gluten rolls suflicient to be 
visible with the naked eye. 

■*Oats. Both common barley and 
oats are known as chaffy cereals to 
distinguish them from naked cereals, 
such as common wheat, rye, and 
maize. It should be noted, however, 
that there are naked varieties of 
barley and chaffy species of wheat, 
although they are not of so common 
occurrence. The Chaff which closely 
invests the kernel is strongly silici- 
fied, as is also true of the stems or 
stalks of all cereals. The kernel 
after removal of the chaff is more 
slender than wheat or rye. 

Histology. The structure of the 
chaff of oats and barley is highly 
interesting and of special impor- 
tance to the food analyst, but need 
not be taken up in this short course. 



CORN 



101 



Suffice it to say that the two can be readily distinguished 
under the microscope. 

None of the layers of the kernel up to the aleurone layer is 
at all conspicuous. The Hairs of the beard, however, are both 
striking and characteristic (Fig. 54, ^). They often reach 2000/i 
in length and are, therefore, twice as long as wheat hairs. They 
taper not only toward the apex but also toward the base, A^hich 
is so narrow as to appear almost pointed. The base of wheat 
hairs is broad. 

The aleurone layer is striking, but not appreciably different 
from the corresponding layer of other cereals. 

The Starch Grains (Fig. 44) of the starch or flour cells resem- 
ble those of rice, but are unlike those of any other cereal. They 
are small (seldom over iom), polygonal, and occur in rounded 
aggregates of from 2 to 100 individuals. As rice does not have 
hairs, at least on the kernel freed 
from the chaff, these furnish a 
ready means of distinguishing 
oat from rice products. From 
all other cereal products the 
starch grains as well as the hairs 
are valuable means of distinc- 
tion. 

Characteristic Elements, (i) 
The hairs narrowed at the base 
(Fig. 54, ^); (2) the polygonal 
starch grains in aggregates (Fig. 

44)- 

*Com (Maize). A longitudi- 
nal section of the Indian corn 
or maize kernel (Fig. 55) shows 
very strikingly the division into 
oily embryo and starchy endo- 
sperm. The plantlet of the 
embryo (at the right), has a distinct Plumule or group of leaves 
at the top {k) and a Radicle or embryonic root below {w) 




Fig. 55. — Corn. Longitudinal section, 
c pericarp; eg horny and ew floury 
endosperm; sc and 55 scutellum of 
embyro; k plumule; w primary root. 
X6. (Sachs.) 



102 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 



At the center it is connected with the Scutellum {ss and sc), 
which draws the dissolved starch from the endosperm during 
sprouting. The Endosperm is partly floury {ew) and partly 







m 



K 



E 




Fig. 56. — Corn. Cross section of bran coats and outer endosperm. Pericarp 
consists of ep epicarp; m mesocarp, p spongy parenchyma, and sch tube 
cells; h spermoderm; is perisperm; endosperm consists of A' aleurone cells 
and £ starch cells. X160. (Moeller.) 




Fig. 57. — Corn. Bran coats in surface view, m mesocarp; sch tube cells; p 
spongy parenchyma; /^ perisperm; A aleurone layer. X160. (Moeller.) 

horny {eg) the latter condition being due to the protein Zein 
in which the starch grains are embedded. The bran coats 
(c), including the aleurone layer, surround the endosperm. 

Histology. The bran coats are shown in cross section and 
surface view in Figs. 56 and 57. The cells of the Outer Layers 



BUCKWHEAT 



103 



{ep and m) in surface view remind us of the outer layers of wheat, 
but they are not so distinct, owing partly to the several layers 
which do not readily separate, and hairs are absent. The 
appearance of these layers in the yellow, white, or red skin will 
soon be learned by experience. The Tube Cells (sch), the loose 
or Spongy Parenchyma (p), and the Aleurone Cells {K) are not 
of special value in identification. The highly characteristic 
Starch Grains (Fig. 45) distinguish corn from all other economic 
products excepting the sorghums, which are not commonly milled. 
They range from 15 to 35ju in diameter and have a very distinct 




Fig. 58. — Buckwheat. Cross section. F pericarp with B bundles; 
derm; £ endosperm; £/» embryo. X16. (Winton.) 



S spermo- 



hilum. In the horny endosperm most of the grains are polygonal ; 
in the floury endosperm most of them are rounded. 

Characteristic Elements, (i) The outer bran coats con- 
sisting of several layers of beaded cells; (2) the polygonal 
starch grains (Fig. 45) up to 35^ in diameter, with distinct 
hilum. Hairs are absent on the kernel although present in 
the chaff which, for the most part, remains with the cob in 
shelling. 

■^Buckwheat. Although not a true cereal, buckwheat yields 
flour and by-products that are put to the same use as those of 
the cereals. The triangular grain is a dry fruit. Unlike the 



104 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 

cereals the black hull or Pericarp is readily removed from the 
seed. The Spermoderm or seed coat is thin and papery of a 
brown or green-brown color. The Embryo is embedded in the 
Endosperm and so folded as to appear in cross section under a 
lens S-shaped (Fig. 58). ♦ 

Histology. The brown elements of the black hulls need not 
be studied. The tissues of the seed coat are shown in Fig. 59. 
Especially noteworthy are the wavy-walled cells of the Outer 




Fig. 59. — Buckwheat. Bran coats in surface view. Spermoderm consists of 
outer epidermis, m spongy parenchyma, and ep inner epidermis; al aleurone 

cells. X300. (MOELLER.) 



Epidermis (0) which, if indistinct in a water mount, are brought 
out clearly by drawing a small drop of 5 per cent sodium hydrox- 
ide under the cover glass. The Spongy Parenchyma (m), with 
greenish or brownish cell contents, is also worthy of notice. 
Aleurone Cells like those of the cereals are present. Buckwheat 
Starch (Fig. 60), is shghtly larger than oat starch, ranging up 
to over 1 5/i in diameter, but the grains are not so sharply polyg- 
onal and, although often united to form rod-shaped bodies, do 
not occur in rounded aggregates. 



PEAS 



105 




Fig. 6o. — Buckwheat Starch. 

X300. (MOELLER.) 



Characteristic Elements, (i) The wavy- walled cells of the 
epidermis (Fig. 59, 0) and (2) the spongy parenchyma {m) 
usually suffice for identification. The absence of rounded aggre- 
gates distinguishes the starch from 
oat and rice starch. 

■^Peas. Beans and peas are true 
seeds. They consist of an outer 
skin or Spermoderm and an Embryo 
with large Cotyledons containing 
reserve starch. No endosperm is 
present in the mature seed, the food 
for the young plantlet having been 
eaten, but not digested as it were, during its development. 

Histology. Fig. 61 shows a 
cross section of the seed coat or 
spermoderm and cotyledon. The 
outer layer of the seed coat con- 
sists of high (6o-ioom) but narrow 
cells forming a so-called Palisade 
Layer (pal). The cavity of these 
cells is narrow except at the base, 
where it is somewhat broadened. 
A curious "Light Line'' (/) follows 
just within the outer surface of the 
layer. The next layer is of cells 
shaped like columns or hour glasses 
{suh). Both the paUsade cells and 
Column Cells are isolated by heat- 
ing a fragment of the skin, 
mounted in 5 per cent sodium 
hydroxide solution, and gently 
pressing the cover glass. After 
this treatment the palisade cells 
fall down on their sides while the 
column cells assume various positions. The relative height of 
the cells of the two layers aids in distinguishing the different 




Fig. 61. — Pea. Outer layers in cross 
section. S spermoderm consists 
of pal palisade cells with / light 
line, siih column cells, and p par- 
enchyma. C cotyledon with am 
starch cells. X160. (Winton.) 



106 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 

legumes. In beans each of the cells, corresponding to the 
column cells of peas, contains a beautiful crystal of calcium 
oxalate. The Starch Grains {am) of the pea are ellipsoidal, 
irregularly swollen, or bean shaped, varying in length up to 
40^. The hilum is elongated, but not so distinct as in beans 
or lentils. Many legumes contain starch, some, such as the 
soy bean and lupine, do not. 

Characteristic Elements, (i) The palisade cells 60 to loo/x 
high (Fig. 61, pal); (2) hour-glass or column cells up to 





I II 

Fig. 62. — Cotton Seed. / cross section. // longitudinal section. 5 spermoderm; 
NE perisperm and endosperm; C cotyledons; R radicle. X4. (Winton.) 

20/X high {sub)\ (3) irregularly ellipsoidal starch grains up to 
40ju {am). 

^Cotton Seed. A considerable number of economic seeds 
are characterized by the presence of oil instead of starch as 
reserve material. These " oil seeds " yield by pressure or 
extraction commercial oils, such as cotton seed, linseed, rape, 
sesame, cocoanut, palm, hemp seed, and poppy seed, which are 
used for foods, drugs, and various technical purposes, while 
the residual cake is commonly utilized for feeding cattle. Oil 
cakes contain a considerable amount of fatty oil which it is 
impracticable to remove and very high percentages of pro- 



COTTON SEED 



107 



tein because of which they are known as " concentrated 
feeds." 




lep- 



FiG. 63.— Cotton Seed. Cross section. S Spermoderm consists of ep epidermis 
with h liair, br outer brown coat with R raphe, w colorless cells, pal palisade 
cells, and a, b, c layers of inner brown coat; N perisperm; E endosperm; 
C cotyledor with aep outer and iep inner epidermis; s resin cavity surrounded 
by z mucilag cells; al aleurone grains; k crystal cells; g procambium bundle. 
X160. (WiNTON.) 

Cotton seed, like the pea, contains its reserve material in its 
Cotyledons, but the starch is replaced by oil. A seed cut in 



108 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 

half with a jack-knife shows the thick black hull, seed coat, or 
spermoderm, and the gray-yellow much-folded cotyledons with 
minute resin cavities appearing as minute black spots (Fig. 62). 
Histology. Fig. 63 shows a cross section through the seed 
coat and cotyledon and Fig. 64, the elements in surface view. 
Two layers are highly characteristic, viz., the Outer Epidermis 
(ep) of the seed coat and the Palisade Layer (pal). 




Fig. 64. — Cotton Seed. Surface view of outer layers, ep epidermis of spermo- 
derm with h^ hair and sto^ stoma; br outer brown cells; w colorless cells; 
pal^ and pal^ palisade cells (see Fig. 63); a, b, c layers of inner brown coat 
of spermoderm; iV perisperm; £ endosperm; af/) outer epidermis of cotyledon 
with h"^ multicellular hair and sto^ stoma. X 160. (Winton.) 

The epidermal cells (Figs. 63 and 64, ep), obtained for study 
by scraping the outer surface of the seed, are of irregular shape 
with dark contents. Among them are the bases of the Hairs 
(Fig. 63, A; Fig. 64, // ^) which remain attached to the seed 
after removing the major part by ginning. These hairs, the 
cotton fiber of commerce, are strap shaped, more or less twisted, 
and have a broad cavity or lumen. 

The palisade cells (Fig. 63, pal) can be secured in suitable 
form for examination either by cutting thin cross sections of 



COTTON SEED 109 

the hull, using a section razor or a Gillette razor blade, or else 
by scraping the hull in a plane at right angles to the surface. 
They are remarkable for their great height (150^1) and their 
division into an outer part of pure cellulose with a distinct cavity, 
about 50M from the end, and an inner lignified part with no evi- 
dent cavity. 

The other layers of the seed coat are of no especial interest. 
The Endosperm (E) is reduced to a single layer of cells resem- 
bling the aleurone cells of the cereals in form and contents. 
The Perisperm (N), or remains of the body of the ovule, also 
consists of but one cell layer. The cell walls are curiously 
fringed. Since both endosperm and perisperm together form 
only a thin colorless coat neither tissue is prominent. 

The bulk of the seed consists of the starch-free oily Embryo. 
In addition to Oil, which has no structure, Aleurone Grains (al) 
and occasional rosette crystals of Calcium Oxalate (k) are pres- 
ent. The aleurone grains are only 2 to Sf^ in diameter and can 
be clearly seen only after removal of the fat from a section with a 
solvent such as ether and mounting in glycerine or else mounting 
directly in olive oil. As this involves considerable labor and with 
rather unsatisfactory results, the student may well reserve his 
study of aleurone grains until he examines flax seed in which they 
are large and quite distinct. The Resin Cavities (Fig. 63, s), 
contain a secretion which dissolves in strong sulphuric acid, the 
solution being blood-red. 

In preparing and examining a mount in sulphuric acid take 
every possible precaution not to get any of the acid on the 
objectives or other parts of the microscope. Use only the low 
power objective and be sure it does not come in contact with 
the cover glass. 

Characteristic Elements. The microscopic elements which 
serve for identification of cotton seed meal are (i) the epi- 
dermal cells of the hull, with yellow walls and dark contents 
(Fig. 64, ep); (2) the palisade cells (Fig. 63, pal); and (3) the 
resin cavities (s), the contents of which dissolve in sulphuric 
acid to a blood-red liquid. 



110 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 

*Fiax Seed or Linseed. In this oil seed part of the reserve 
material is in the Endosperm (Fig. 65, £), and part in the Em- 
bryo (C). Figs. 66 and 67 show the seed coat and endosperm in 
cross section and surface view. 

The Epidermis (Fig. 67, ep ^) of the seed coat consists of 




Fig. 65. 



Fig. 66 



Fig. 65. — Linseed in Cross section. 5 spermoderm or seed coat; E endosperm; 

C cotyledons. (Moeller.) 
Fig. 66. — Linseed. Cross section of 5 spermoderm and E endosperm, ep outer 

epidermis; p round cells; / fiber layer; Ir cross cells; g pigment cells. 

(Moeller.) 



transparent, glassy cells. More readily found are the longi- 
tudinally arranged Fibers (/) with thick walls and ragged cavity, 
the thin- walled Cross Cells (tr), and the Round Cells (r). Often 
these three layers may be seen in the same fragment of the hull, 
by careful focusing. Equally striking are the more or less 
square Tannin Cells (pig). These have indistinctly beaded 
walls and brown contents. It should be noted that none of 



FLAX SEED 



111 



the cells is perfectly square, but rather five or six sided with 
one or two of the walls much reduced in length. A perfectly- 
square vegetable cell is physiologically as impossible as a square 
honey-comb cell. 

A razor section of the seed mounted in olive oil, or some other 




f^QuJi)^ 



Fig. 67. — Linseed. Elements in surface view, cp^ epidermis of spermoderm; 
r round cells; / fiber layer; x middle lamellae of fiber layer; Ir cross cells; 
pig pigment cells; E endosperm with al aleurone grains; ep^ epidermis of 
cotyledon with slo immature stoma; nics mesophyl. X300. (K. B. Winton.) 



fatty oil, or else in turpentine or glycerine (one of which will 
serve for the class) shows the large Aleurone Grains, of the 
endosperm and embryo (Fig. 66, E). They range up to 20^ in 
length. Aleurone grains are not, like starch grains, homogeneous 
in chemical composition. Each grain consists of a ground sub- 
stance in which are usually embedded one or more Crystalloids 



112 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 

or protein crystals, one or more Globoids (compounds of lime and 
magnesia with phosphoric acid and an organic acid), and often 
crystals or crystal rosettes of Calcium Oxalate. In the aleurone 
grains of linseed only one globoid and one indistinct crystalloid 
are present. 

Characteristic Elements, (i) Fragments consisting of fibers 
(Fig. 67,/), cross cells (tr), and round cells (r); (2) nearly square 
tannin cells with brown or yellow contents (pig). 

"^Black Pepper. The chief characters of four of the prin- 
cipal spices — black pepper, cayenne pepper, cinnamon, and gin- 
ger — can be observed in a single exercise; the detailed struc- 
ture, which could scarcely be mastered in a week, would for our 
purpose be of little more value. 

Black pepper is the dried immature berry of a vine growing 
in the Orient. White pepper is the mature 
berry from which the hull has been re- 
moved. The reserve material is in the 
form of starch and is contained, not in the 
endosperm as in wheat or in the embryo 
Fig. 68.— Black Pepper, ^s in the pea, but in the Perisperm (Fig. 
ongi u ina sec ion ^g^ ^^^ ^-^^ robustly developed body of 

sperm; N perisperm; the ovule which in most plants largely dis- 

FS pericarp and appears on ripening. 

spermoderm. X 3- Histology. Fig. 69 shows the elements 

(MOELLER.) ^ 1,1, T 1 , 1 

of ground black pepper. Just below the 
Epicarp or epidermis of the berry is a layer {ast) consisting 
largely of Stone Cells, a kind of cell with thick lignified walls 
and branching cavities, widely distributed through the vege- 
table kingdom. The small but hard granules encountered in 
eating a pear or quince are groups of stone cells and the tough 
character of raspberry and strawberry " seeds " is due to a 
protective stone cell layer. Stone cells make up the bulk of nut 
shells (cocoanut, walnut, etc.), fruit stones exclusive of the 
kernel (peach, olive, etc.), the woody part of maize cobs, and 
various hardened tissues, but not of true wood. Stone cells 
of different products vary in form and size and in the thickness 




BLACK PEPPER 



113 



and color of the walls and the nature of the cell contents. Because 
of these differences the trained microscopist can detect in ground 
pepper the presence of adulterants such as ground cocoanut 
shells and ground olive stones, which were formerly added in 
large quantities. 

A second layer of stone cells (ist) occurs in the inner portion 



a/u 



ist--- 




¥ 






9 <^ 
Fig. 69. — Black Pepper. Elements of powder, ep epicarp; ast hypodermal stone 
cells; bf bast fibers; hp bast sclerenchyma; sp vessels; p oil cells; ist endo- 
carp; is and as layers of spermoderm; am starch masses. X160. A starch 
grains, X 600. (Moeller.) 



of the hull. This portion is not removed in decortication, hence 
the stone cells occur in white as well as black pepper. As only 
the inner and side walls are thickened they are known as Beaker 
Cells. This character is not evident in surface view of the stone- 
cell groups, but only when individual cells become detached as 
shown at the right of the group shown in the figure. 



114 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 

The bulk of the pepper corn consists of a mass of Starch Cells. 
The ground product contains groups of cells with contents 
intact {am) , also the starch separated from the cells as individual 
grains or groups of grains (A). The individual grains are 
among the smallest found in economic products, being usually 
2 to 4 M in diameter and never ejiceeding 6/i. Needle-shaped 
crystals of Piperine are often evident in ground pepper. 




Fig. 70. 



Fig. 71. 



Fig. 70. — Cayenne Pepper. Epicarp in surface view. X160. (K. B. Winton.) 
Fig. 71. — Cayenne Pepper. Epidermis of seed in surface view. X160. (K. B. 

Winton.) 



Characteristic Elements, (i) The stone cells (Fig. 69, ast) of 
the outer layer; (2) the beaker-shaped stone cells {ist); (3) the 
starch cells {am)\ (4) the Hberated starch (A) with minute grains. 

■^^Cayenne Pepper. The highly pungent chillies, or fruits 
of a small podded species of Capsicum grown in Africa, are 
known in commerce as cayenne pepper or cayenne. The mild 
fruits of a large podded variety of the garden pepper grown in 
Hungary yield paprika. 

Histology. Both kinds of red pepper are non-starchy and 



CINNAMON 115 

contain in the pod tissues drops of Oil which take on an orange- 
red coloring matter also formed in the cells. Mounted in 
concentrated sulphuric acid the oil drops become indigo blue. 
The tissue characteristic of cayenne alone is the Epicarp, or 
outer epidermis of the pod, consisting of more or less rectangular 
cells with wavy walls (Fig. 70). 

The Epidermis of the seed consists of remarkable cells with 
curious, wrinkled walls resembling the convolutions of the 
intestines (Fig. 71). As seen in surface view these cells are 
much alike in cayenne and paprika, but no such cells occur in 
any other common food product. The seed tissues containing 
oil and aleurone grains are not remarkable. 

Characteristic Elements, (i) The more or less rectangular 
cells of the epicarp with wavy walls (Fig. 70) ; (2) the orange- 
red oil drops becoming indigo blue with sulphuric acid; (3) the 
intestine cells of the seed (Fig. 71). 

^Cinnamon. The moderately thick bark which in import 
trade is designated cassia when ground is known to the house- 
wife as cinnamon. True or Ceylon cinnamon is a very thin 
bark used chiefly in medicine. 

Histology. The scientific study of barks involves a knowl- 
edge of the so-called Fibro-vascular Bundles, forming the con- 
ductive system of plants. Such a study, although highly 
interesting, would carry us beyond the limits of our work. 
For diagnostic purposes we need consider only such elements 
as are most conspicuous in the powdered material, namely 
the bast fibers, the stone cells, the cork cells, and the starch 
grains. 

The Bast Fibers (Fig. 72, bf) resemble stone cells in general 
structure and chemical composition, but are elongated, pointed 
at both ends, and have a smooth (not branching) cavity. The 
flax fibers used in making linen fabrics are bast fibers. 

The St07ie Cells are either thickened on all sides (st) or only 
on one side (stp). Cork Cells (P) are present if the bark has not 
been deprived of its outer layers by scraping. The cork of 
commerce is the highly developed cork layer of an oak grown in 



116 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 

Spain. Owing to the infiltrated Suberin, cork cells repel water 
and form a protective coat for the tree or plant. All the pre- 
ceding elements are best seen after treating a water mount 
with sodium hydroxide; the starch, however, must be examined 
in the water mount. 

The Starch Grains (B) range usually from lo to 20^1 in diam- 
eter, and occur mostly in aggregates of 2 to 4 individuals. They 




Fig. 72. — Cinnamon. A elements of powder: bf bast fibers; st and stp stone 
cells; pr and bp parenchyma; P cork. X160. B starch grains, X600 

(MOELLER.) 



have rounded or flat sides according to their location in the 
aggregates. A distinct hilum is evident. 

Characteristic Elements, (i) Bast fibers (Fig. 72, bf); (2) stone 
cells (st, stp); (3) starch grains (B), 10 to 20/i, with distinct 
hilum, occurring mostly in aggregates of 2 to 4. 

■^Ginger. The dried underground stem or root of the 
ginger plant comes into the market simply washed or else 
scraped. A coating of chalk is added to some varieties the prod- 
uct thus limed, being, it is claimed, less susceptible to the attacks 
of insects. 

Histology. The rootstock consists in large part of paren- 



GINGER 



117 



chyma cells filled with Starch Grains which are characteristic 
because of the rounded angle at one end (Fig. 73, am). Most of 




Fig. 73. — Ginger. Elements of powder, p parenchyma with starch grains and 
ol oil masses; am starch grains; / bast fibers; sea vessels; pig pigment; 
su cork. X160. (K. B. Winton.) 



7>/s. 



Mk 






Em 
II 

Fig. 74. — Coffee. I cross section of berry, natural size. Pk outer pericarp; 
Mk endocarp; Ek spermoderm; Sa hard endosperm; Sp soft endosperm. 
// longitudinal section of berry, natural size; Dis bordered disc; Sc remains 
of sepals; Em embryo. Ill embryo, enlarged: cot cotyledon; rad radicle. 
(TscHiRCH and Oesterle.) 



the grains are egg shaped and 2'o to 30/1 long, although smaller 
and larger grains (up to 50/x) occur sparingly. The fibrous 



118 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 

material of the rootstock contains Vessels (sea) with reticulated 
thickenings and Bast Fibers (/) with rather thin walls and broad 
cavities. 

Characteristic Elements. (i) Starch grains with rounded 
angle at one end (am); (2) reticulated vessels (sea); (3) bast 
fibers (/) with thin walls and broad cavity. 

^Coffee. In a laboratory period the student can not only 










Fig. 75. — Co£fee. Spermoderm in surface view, st stone cells; p parenchyma 

X160. (MOELLER.) 



learn the general structure of coffee and cocoa, but also the 
use of the section razor in studying these products. Fig. 74, 
I and II, shows cross and longitudinal sections of a coffee berry 
or " bean " natural size. The shelled bean consists of the hard 
endosperm in which is embedded a minute embryo (III). 

Histology. The papery fragments of the spermoderm or 
seed coat, which will be found in the cleft of a coffee bean, 



COFFEE 



119 



should first be examined. Scattered here and there over the 
skin are remarkable Stone Cells of various shapes with porous 
walls and broad cavities (Fig. JS, st). Often two or more of the 
cells are in groups. 

The structure of the endosperm is best seen in a cross sec- 
tion. Such sections can be secured by holding a coffee bean, 
which has been softened by soaking or boiling in water, between 
the thumb and first finger of the left hand and cutting the thin- 
nest possible shavings with a section razor or Gillette blade 
held with the right hand. Considerable experience is required 
for cutting satisfactory sections of certain seeds, but a little 
practice should enable the student to prepare sections of the 
coffee bean thin enough to show the general character of the 
cells. 

It will be noted that the cell walls (Fig. 76) are not only thick, 
but have a beaded ap- 
pearance due to the pits 
or pores which pierce 
them, thus furnishing 
communication from one 
cell to another. The 
thickened cell walls con- 
stitute the chief reserve 
material which, instead 
of being in the form of 
starch or oil, is in the 
form of cellulose or re- 
lated carbohydrates. Sec- 
tions can be cut of small 

fragments if held between flat pieces of cork. In this manner 
ground coffee can be distinguished from common adulterants and 
substitutes, such as peas and wheat. As a preliminary test, 
a teaspoonful of the sample should be stirred in a glass of 
cold water. Peas, cereals, and chicory will sink at once, while 
coffee floats. Chicory quickly imparts to the water a dark color. 

Characteristic Elements, (i) Stone cells of the papery seed 




Fig. 76. — Coffee. Cross section of outer layers 
of endosperm showing knotty thickenings of 

cell walls. X160. (MOELLER.) 



120 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 

coat (Fig. 75, st); (2) reserve cellulose in the form of knotty 
thickened or beaded walls of the endosperm (Fig. 76). 

•*Cocoa Bean. The seed of the cocoa or cacao tree, known 
as the cocoa bean (Fig. 77), consists of a leathery hull or shell 
and an embryo with folded but fleshy cotyledons containing 
the reserve material, which is partly starchy and partly oily, 
the latter predominating. Cocoa beans yield after roasting, 
shelling, and grinding, the chocolate of commerce. The heat 




Fig. 77. — Cocoa. 7 entire fniit, Xi; // fruit in cross section. Ill seed (cocoa 
bean), natural size; IV seed deprived of spermoderm ; V seed in longitudinal 
section, showing radicle (germ); VI seed in cross section. (Winton.) 



of the grinding melts the fat or cocoa butter, and as a con- 
sequence, the product which runs from the mill is a thick paste, 
which hardens on cooling to a waxy mass known as plain or 
bitter chocolate or chocolate liquor. 

Cocoa is the cake remaining after pressing out about half 
of the fat, reduced to a powder. 

Histology. Fragments scraped from the shell of a cocoa 
bean should first be examined. In these will be seen numerous 
spirals, like spiral springs, which are the thickenings of Spiral 
Vessels. These give rigidity to the vessels, serving the same 



COCOA 121 

purpose as the spiral iron wires in the flexible pipes for gas 
drop lamps. Spiral vessels occur also, but sparingly, in black 
pepper (Fig. 69, sp). 

Cross sections should then be cut of the cotyledons without 
soaking, the high percentage of fat being sufhcient to make them 
soft, yet firm. These sections may be examined directly in 
water, but the fat will greatly interfere with the observation. 
It is better to remove the fat from the section, previous to 




Fig. 78. — Cocoa. Cross section of outer portion of cotyledon, sho\ving hairs and 
starch parenchyma. (Moeller.) 

mounting in water, by treating with several successive portions 
of ether or chloroform in a watch-glass, or else to mount in 
turpentine. In either case the starch grains will be evident, 
but the water mount of the extracted sections has the advantage 
that the iodine test can be applied. 

Cocoa Starch (Fig. 78) resembles that of cinnamon. The 
grains are 4-1 2/x in diameter, and occur in aggregates of two to 
four individuals. Because of their grouping into aggregates, 
they often have both rounded and angular outlines. 



122 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 



Characteristic Elements, (i) Numerous spiral vessels in the 
shells; (2) starch grains 4-1 2/i in diameter with evident hilum, 
occurring in small aggregates. 

*Tea. Both black and green tea consist of the dried leaves 
of Thea Chinensis, the difference in color being due to the 
process of drying. The leaves (Fig. 79), 
as may be seen by spreading out the 
moist residue after preparing the beverage, 
are rather thick, glossy on the upper sur- 
face, short-toothed, and veined in such a 
manner that the main veins branching off 
from the midrib form near the margin 
loops, connecting them with adjoining 
veins. 

Histology. The structure of leaves 
bears an obvious relation to their function, 
namely, Photosynthesis, the formation of 
carbohydrate matter from carbon dioxide 
of the air and water of the soil in the 
sunlight through the agency of chlorophyl 
grains. 

Fig. 80 is a cross section of a tea leaf 
through a Stoma. Beneath the stoma there is an air space 
surrounded by loosely arranged cells containing Clilorophyl 
Grains, and often crystals of Calcium Oxalate. It is here that 
photosynthesis takes place. A large curiously formed Stone 
Cell extends from one epidermis to the other. Other forms of 
stone cells are seen at the right {st). 

A surface section of the lower epidermis (Fig. 81) shows 
several stomata {sp), also a Hair (//) bent near its base like 
a cane handle. 

Characteristic Elements. All of the elements named may 
be found in the debris obtained by scraping a moist tea leaf. 
The curious stone cells and the hairs are characteristic. 

■^^Examination of Mixtures in Powder Form. Various mix- 
tures should be made of the following: wheat flour, buckwheat 




Fig. 79. — Tea. Leaf, nat- 
ural size. (MOELLER.) 



MIXTURES 



123 



flour, maize flour, ground wheat bran, ground rye bran, ground 
oat meal, ground peas, cotton seed meal, linseed meal, ground 



oep 




Fig. 8o. — Tea. Cross section of leaf, icp lower epidermis with / hair and sio 
stoma; mes mesophyl with chlorophyl grains, large stone cell, and cr calcium 
oxalate rosette; hit intercellular space; oep upper epidermis; st isolated 
stone cells. Xi6o. (Winton.) 




Fig. 8r. — Tea. Leaf seen from below, showing epidermis, with h hair and sp 
stoma, and m mesophyl. Xi6o. (Moeller.) 

black pepper, ground cayenne pepper, ground ginger, ground 
cinnamon, and cocoa. Mixtures of more than two of the 
materials seem inadvisable, at least if only a day can be de- 



124 MICROSCOPIC EXAMINATION OF VEGETABLE FOODS 

voted to the work of identification. In order that the color 
may not furnish a clue to the ingredients, pigments such as 
yellow ochre, burnt sienna, and lampblack may be added 
to some of the mixtures. Only such mixtures should be pre- 
pared as correspond to products now or formerly on the market. 
Ground coffee, pure and mixed with roasted ground peas or 
roasted wheat, may also be used for practice material. 

An examination should first be made of a water mount, 
before and after staining with iodine, to determine whether 
or not starch is present and, if so, the kind. A drop of sodium 
hydroxide can then be drawn under the cover glass and the 
tissues examined. Reference should be made to the para- 
graphs of the preceding descriptions, giving the " Character- 
istic Elements " of the products, in interpreting the results of 
the observations. 

The following hints may be useful: If lenticular starch 
grains 30 to 50/i and hairs with broad bases are found, wheat 
or rye is present. If further search discloses a considerable 
number of starch grains over 50/x, these are doubtless from rye. 
In any event cross cells should be looked for, and the char- 
acters distinguishing wheat from rye noted. As the small 
starch grains of wheat and rye resemble buckwheat starch, 
search should be made for the tissues of the buckwheat seed 
coat, especially the wavy-walled cells and green-brown spongy 
parenchyma. Oat starch might also be confused with the 
small grains of wheat and rye or buckwheat starch, were it 
not for the presence of aggregates of numerous individuals; 
furthermore the long oat hairs with narrow, almost pointed, bases 
are characteristic. Bean-shaped starch grains with elongated 
hilum indicate peas (knowing other leguminous seeds to be 
absent) and large (up to 35^) polygonal grains are evidence of 
maize. Pea hulls in the ground product will be indicated by 
the presence of isolated palisade cells and hour-glass cells. 
Cotton seed and linseed meals contain no starch, but the 
tissues of the seed coat leave no doubt as to their identity. 

Of the spice starches, that of pepper is minute, of cinnamon 



MIXTURES 125 

larger and in small aggregates, and of ginger large with a 
rounded angle at one end. Cayenne contains no starch but 
the orange oil drops, the epicarp, and intestine cells are char- 
acteristic. The stone cells of pepper and the bast fibers as 
well as the stone cells of cinnamon should be noted. Broad 
bast fibers and curious vessels are present in ginger. An added 
cereal or oil seed product may be looked for in spices, also 
wheat or maize flour in cocoa. 

Roasted peas, or wheat if present in ground coffee, sink 
in cold water. The presence and characters of the starch 
and the elements of the hulls or bran furnish more specific 
information. Chicory also sinks in cold water-imparting a 
brown color. 



CHAPTER VI 
SACCHARINE PRODUCTS 

Sugar 

Characters of Sucrose. Since, at the present time, the world's 
product of commercial sugar is obtained in about equal quan- 
tities from the sugar cane and the sugar beet, and further- 
more, the same sugar is also produced by the sugar maple tree, 
the frequent use of the term cane sugar as a synonym for sucrose 
is confusing. 

Sucrose is a disaccharide with the empirical formula C12H22O11. 
It is dextrorotatory, that is, a water solution turns a ray of 
polarized light to the right. Treatment with 2.5 to 4 per cent 
hydrochloric acid at 69° C. for five to fifteen minutes or at 
20° C. for one or two days inverts sucrose, causing it to spUt 
up into one molecule each of Dextrose ((^-glucose) and Levulose 
((/-fructose) as shown by the following equation: 

Cl2H220ll+H20=C6Hi206+C6Hi206. 

Although the two cleavage products have the same em- 
pirical formula, dextrose is an aldehyde (aldose) and dextro- 
rotatory, while levulose is a ketone (ketose) and levorotatory. 
The fact that both dextrose and levulose reduce Fehling's copper 
solution, while sucrose does not, is explained by the hypothesis 
that the two radicles in the latter are so combined as to destroy 
the aldehyde group of the one and the ketone group of the 
other. 

This difference in configuration is brought out strikingly 
by the following structural formulae of the three sugars: 

L27 



128 



SACCHARINE PRODUCTS 



CH2OH 

I 
HOCH 

HOCH 

HCOH 

HOCH 

CHO 



Dextrose 
(d-glucose) 



CH2OH 

HOCH 

HOCH 
HCOH 
C=0 
CH2OH 



Levulose 
(d-fructose) 




Sucrose 



The copper-reducing power of dextrose is slightly greater 
than that of levulose; on the other hand, the levorotatory 
power of levulose at ordinary temperatures is considerably more 
than the dextrorotatory power of dextrose, consequently Invert 
Sugar, the mixture of equal molecules of dextrose and levulose, 
is levorotatory. 

The characters which have been briefly stated are the basis 
of the most important analytical methods used in sugar analysis. 
Sucrose is calculated from the figures obtained by polariza- 
tion, both before and after inversion, while dextrose, levulose, 
and invert sugar are commonly determined by copper reduc- 
tion. 

The Polariscope. The instrument used in sugar analysis 
known as the Saccharimeter is graduated in terms of per- 
centages of sucrose, using definite amounts of the material 
and diluting the solutions to definite volumes. A full consid- 
eration of the construction of the different types of saccharimeter 
and the optical principles involved would more than fill the 
pages of this volume. As is also true of the microscope, there 
is no more necessity of the student understanding fully the 
detailed construction or optics of the instrument, than for an 
artist to understand the anatomy, physiology, and optics of 
his own eyes. The following brief statements may add interest 
to the work. 



SACCHARIMETER 



129 



Fig. 82, taken from Browne's Ha?idhook of Sugar Analysis, 
is a diagram of the simplest form of polariscope. The light 
from the lamp L is polarized by the Nicol prism P, known 
as the polarizer, that is, the light vibrations which are normally 
in different planes are reduced to one plane. Another Nicol 
prism, A, known as the analyzer, is so arranged that it can 
be rotated about the longitudinal axis of the instrument. With 

sf 



I ^ 



Fig. 82. — Diagram of a Simple Polariscope. 



the sugar tube T empty, the light polarized by P, as seen by 
the eye at E, is not altered by A when the axes of the two 
prisms are parallel; when, however, the axes are crossed, the 
light is extinguished. If with crossed prisms, a sugar solu- 
tion is placed in T, the ends being closed by circular glasses, 
the Ught is no longer extinguished, but passes through with 
greater or less intensity, dependent on the nature and amount 
of the sugar. On turning the analyzer so that the field is again 
black, the amount of rotation 
due to the sugar solution can be 
read on the circular scale S. 

The chief difficulty with an 
instrument of this simple con- 
struction would be to determine 
the point where the field is 
darkest. To obviate this defect a half-shadow device with a 
double-field is employed, whereby the left half of the field is 
dark and the right half is light when the analyzer is crossed 
with the left half of the field (Fig. 83, /), while the reverse is 
true when the analyzer is crossed with the right half of the 
field (Fig. 83, II). The zero point, when the tube is empty. 




I n III 

Fig. 83.— Double Field of Half-shadow 
Saccharimeter. 



130 



SACCHARINE PRODUCTS 



and the end point, when an analysis is being made, is shown 
by the exact correspondence of the two halves of the field 
(Fig. 83, III). 

A further improvement is the double-wedge system, in 
which both analyzer and polarizer are fixed, and the end 
point is obtained by sliding one quartz wedge alongside of an- 
other until the thickness of the two is such that the quartz 




Fig. 84. — Double- wedge Soleil-Ventzke Saccharimeter with Bock Stand and Electric 

Lamp. 



rotates the light to the same degree as the sugar solution. 
The reading is taken on the scale or scales with which the 
wedge device is provided. Fig. 84 shows a modern instrument 
with double-field and double-wedge device. 

* Polarization of Granulated Sugar before and after In- 
version. The best granulated sugar is practically pure 
sucrose. It contains only traces of water, ash, and reducing 
sugars. 

Weigh out in a nickel sugar dish (Fig. 85) the normal quan- 



SUGAR 



131 



tity of sugar for the type of saccharimeter used (26 grams for 
the Soleil-Ventzke saccharimeter), transfer through a funnel 
to a loo-cc. graduated flask, rinsing out any that may adhere 
to the funnel with water. Add enough water to dissolve the 
sugar and make up to the mark 
and shake. 

Direct Polarization. Remove 
the cap and cover-glass from one 
end of a 200-mm. observation tube 
(Fig. 86) , fill with the sugar solu- 
tion, slide the cover glass into 
place, and attach the cap. 

If the tube has one end enlarged as shown in Fig. 86, it is 
not necessary to avoid an air bubble in the tube, as this will 
rise, when the tube is in a horizontal position, into the ex- 
panded part of the tube and thus be out of the line of vision; 
if, however, both ends are the same size (Fig. 87) the tube 




Fig. 85.- 



-Nickel Sugar-weighing Dish 
and Counterpoise. 




Fig. 86. — Saccharimeter Tube with Enlarged End. 




Fig. 87. — Saccharimeter Tube, Simple Form. 



must be completely filled and the cover glass slid into place 
in such a manner as to exclude any air bubble. 

Place the tube in the polariscope, light the lamp, adjust one 
scale at o, and move the other until the end point is reached. 
The reading should vary only sHghtly from -f 100. 

Polarization after Inversion. Pipette 50 cc. of the sugar 
solution and 25 cc. of water into a loo-cc. graduated flask, 
add 5 cc. of concentrated hydrochloric acid, mix, place a ther- 



132 SACCHARINE PRODUCTS 

mometer in the solution, and heat in a water bath at 72° to 
73° C, so that the solution reaches 69° in 2^ to 5 minutes. 
Maintain at 69° C. for five minutes, remove the flask, cool rapidly 
to 20° C. under a stream of cold water, and dilute to 100 cc. 

Polarize in a 200-mm. tube as before inversion, but multiply 
the reading, which will be to the left (expressed by the minus 
sign), by 2 to compensate for the dilution from 50 cc. to 100 
cc. Immediately after taking the reading, plunge a ther- 
mometer in the solution to determine the exact temperature. 
If the polarization is determined at exactly 20° C, the reading 
multiplied by 2 should vary only slightly from —32.7. 

We are now in a position to understand the Herzfeld-Clerget 
formula, as follows: 

<j,_ ioo(a — b) 
142.66— //2' 

in which S = per cent of sucrose, a = direct polarization (with 
+ sign), 6= invert polarization (with— sign), and /=the tem- 
perature. 

a—b, being the algebraic difference, will be the sum of the 
direct (-f-) and invert (— ) polarization. If the work has been 
carefully performed, the percentage of sugar by direct polari- 
zation, as well as by the above formula, will be practically 100. 

In a case such as the preceding, where only sucrose is present, 
the inversion is not necessary for the correct result; if, how- 
ever, another sugar, such as dextrose or invert sugar, is present, 
the result of the direct polarization is not the percentage of 
sucrose, but a meaningless resultant figure, whereas the Herz- 
feld-Clerget formula automatically corrects for the polarization 
of the foreign sugar or sugars and gives the true percentage of 
sucrose. This is readily understood when it is noted that 
both the reading a and the reading b consist in part of the 
same figure, namely the polarization of the foreign sugar. As 
this figure is introduced twice with opposite signs, its influence 
is eliminated from the equation, and the result due to the 
polarization of the sucrose alone is obtained. 



MOLASSES, SYRUP, AND HONEY 133 

Molasses, Syrup, and Honey 

Chemical Composition. Molasses and Sugar House Syrups 
are solutions of sucrose with some reducing sugars and various 
other impurities. Lead subacetate precipitates the bulk of the 
nonsaccharine impurities which give the product its dark color. 

Cormnercial Glucose or Corn Syrup is prepared by the action 
of dilute hydrochloric acid on starch, the acid being subsequently 
neutralized by sodium carbonate with the formation of ordi- 
nary salt. Its solid matter consists of a mixture of maltose, 
dextrine, and dextrose, all of which are dextrorotatory. The 
product used for mixtures such as Karo Syrup, is known as 
42° Baume mixing syrup and polarizes from 162° to 175° on 
the sugar scale. 

Honey consists essentially of the sucrose from the nectar 
of flowers inverted in the body of the honey bee. It is 
levorotatory. Hawaiian honey-dew honey and unimportant 
varieties made from the blossoms of certain trees are often 
dextrorotatory. 

^Determination of Sucrose in Molasses, Syrup, and Honey. 
Material for Laboratory Practice. Provide for practice material 
a good grade of molasses, the product known as Karo Syrup, 
or a similar mixture of about 90 parts of commercial glucose 
or corn syrup and 10 parts of cane syrup, and pure strained 
honey (not Hawaiian) . 

Method of Clarification. In order to polarize colored or 
turbid products, such as molasses, syrups, and honey, it is 
necessary first to clarify them, that is, to remove the larger 
part of the coloring matter and all of the suspended or colloidal 
impurities. 

Weigh out in a nickel sugar dish normal quantities (26 
grams) of the molasses and honey and a half normal quantity 
of the syrup. Transfer with the smallest possible amount of 
water to loo-cc. graduated flasks. To the molasses and syrup 
add with shaking lead subacetate solution (sp.gr. 1.25) in slight 
excess (5 to 10 cc.) and i cc. of alumina cream (aluminum 



134 SACCHARINE PRODUCTS 

hydroxide suspended in water) ; to the honey add only alumina 
cream. Make up to the mark, shake, and filter through dry 
filters into dry flasks. Instead of the solution of lead subace- 
tate the powdered dry salt, as recommended by Home, may 
be added, after making up to loo cc, until no further precipi- 
tation is noted. For the preparation of alumina cream a 
solution of aluminum soaium sulphate is precipitated with 
ammonia water, washed by decantation until sulphates are 
removed, and finally decanted down to the precipitate. 

Direct Polarization. Polarize the filtrates as described for 
granulated sugar (p. 131). Note that the molasses and syrup 
are dextrorotatory, the syrup being strongly so, although 
only half the normal quantity was used, while the honey is 
levorotatory. 

A little practice is required in manipulating the scales to 
distinguish right- and left-handed polarization. As different 
instruments have different mechanisms the student must de- 
pend upon the instructor or his own experience in such details. 

Invert Polarization. Free portions of the solutions clari- 
fied with lead subacetate from lead by adding finely powdered 
potassium oxalate with shaking until no further precipitate 
forms. Filter through dry filters into dry flasks. The process 
of inversion may be conducted at 69° C. exactly as in the in- 
version of granulated sugar. However, in order to vary the 
manipulation and divide the work between two days, the 
inversion should be carried out at room temperature as fol- 
lows: Place 50-cc. portions of the solutions (deleaded in the 
case of the molasses and the syrup) in loo-cc. flasks, add 5 cc. 
of concentrated hydrochloric acid, mix, and allow to stand over- 
night (at least twenty-four hours), at a temperature not below 
20° C. 

Dilute to 100 cc, polarize, and calculate sucrose by the 
Herzfeld-Clerget formula, as described for granulated sugar 
(p. 132). Note that the invert polarization of the molasses 
is to the left, while that of the Karo Syrup is still to the right, 
although less than before inversion. The polarization of the 



MAPLE PRODUCTS 135 

honey is not greatly affected by the inversion. The calculated 
amount of sucrose in the molasses should be between 30 and 
55 per cent, in the Karo Syrup about 10 per cent (or the amount 
declared on the label), and in the honey a very small amount, 

if any. 

^Calculation of the Total Solids in Molasses, Syrup, and 
Honey from the Refractive Index. The Abbe refractometer, 
being most commonly used in the examination of fats and oils, 
is described in Chapter VII. Determine the refractive index 
as described for oils (p. 149) and calculate the total solids by 
means of Geerlig's table (p. 224), correcting the results for tem- 
perature in accordance with the table on p. 225. 

The drying of saccharine products in an ordinary water oven 
at 100 ° C. is a slow operation. If levulose is present, the 
results are inaccurate, owing to the decomposition of that sugar. 
This error can be obviated by drying at 70° C. in a vacuum 
oven, but the apparatus is expensive and troublesome to main- 
tain. All drying methods are tedious. The calculation from 
the refractive index is convenient and sufficiently accurate for 
practical purposes. 

Maple Products 

Source. The sap of the sugar maple tree is rich in sucrose 
and contains in addition certain characteristic flavoring con- 
stituents. On evaporation Maple Syrup and Maple Sugar are 

obtained. 

Because of the increased demand and consequent high price 
of maple products, cheaper saccharine products are mixed with 
them, thus diluting the flavor although not reducing the food 
value. Formerly glucose was used, but at the present tune 
refined sugar syrup is preferred. 

Analysis of Maple Products. As the sugar of the sugar 
cane, sugar beet, and maple tree are identical, determmations 
of sucrose are of no value in the examination of maple prod- 
ucts with reference to the admixture of refined sugar. Depend- 
ence must therefore be placed on the character and amount 



136 SACCHARINE PRODUCTS 

of minor constituents. Fortunately for the consumer, it is 
impracticable to add molasses or sugar-house syrup, as these 
have strong flavors that would conceal the delicate maple 
flavor. Being forced to use refined sugar, the detection of a 
considerable admixture is readily accomplished by determina- 
tions of Ash and Lead Number, the latter being a measure of 
the constituents precipitated by basic lead acetate. Refined 
sugar contains practically no ash and no constituents precipi- 
tated by lead salts. 

Fruit Syrups 

■^Artificial Colors in Fruit Syrups. The coloring of foods 
with vegetable, animal, and coal-tar dyes has been a matter of 
much concern to food chemists. In certain foods such as fruit 
products the dyes used conceal inferiority or adulteration, while 
in other foods such as confectionery, the purpose is merely to 
please the eye. 

Certain State laws allow only vegetable and animal colors. 
Most State food laws and the regulations of the Federal Food and 
Drugs Act permit the use not only of harmless vegetable and 
animal colors, but also certain coal-tar dyes provided their 
presence is declared on the label and they are not used to con- 
ceal inferiority. 

Fruit syrups, especially those used for soda water, are often 
colored and may be used as representative products for labora- 
tory practice. 

^Material for Laboratory Practice. The following should 
be provided for use of the class: 

1. Pure Raspberry or Strawberry Syrup. If a product of 
known purity is not obtainable express the juice of the fruit, 
add sugar, and boil down to a syrupy consistency. Lacking 
the fresh fruit, jam may be used as the basis of the syrup. 

2. Simple Syrup (prepared by treating granulated sugar 
with water in the proportion of loo grams of the sugar to about 
60 cc. of water) colored with cudbear. 

3. Simple Syrup colored with cochineal. 



FRUIT SYRUPS 137 

4. Simple Syrup colored with amaranth. 

5. Simple Syrup colored with ponceau 3R. 

6. Simple Syrup colored with erythrosin. 

7. Simple Syrup colored with orange I. 

8. Simple Syrup colored with naphthol yellow S. 

The amounts of the artificial red dyes used in 2 to 6, inclusive, 
should be sufficient to impart to the syrups a red color of about 
the intensity of that of the raspberry syrup; the amount used 
in 7 and 8 should be sufficient to color the syrups bright orange 
and yellow shades. Federal regulations permit the addition to 
foods of all the dyes enumerated. In addition to the five coal- 
tar colors (4 to 8, inclusive), three others (light green S. F., yel- 
lowish, indigo disulphoacid or indigo carmine, and tartrazine) 

may also be used. 

Syrups 2 to 8, inclusive, will give the same results m dye- 
ing tests as imitation fruit syrups flavored with fruit ethers 
and containing the colors named. 

^Arata's Wool Dyeing Test. Dilute 10 to 25 cc. of the 
syrup to 100 cc, add 10 cc. of a 10 per cent solution of potassium 
bisulphate and a piece of white woolen cloth (nun's veilmg or 
albatross cloth), about i in. square, which has previously been 
heated to boiUng in a o.i per cent solution of sodium hydroxide 
to remove any grease. Heat to boiling and boil for about 
fifteen minutes. Remove the wool, boil first with water, then 
with a solution of an alkah-free soap, and finally agam with 
water. Dry and note the color. 

The coal-tar colors will dye the cloth bright red, orange, or 
yellow shades, whereas the cudbear dyes it a dirty red color, the 
cochineal a pinkish color, and the natural color of the raspberry 

scarcely at all. r u j j 

A few drops of ammonia added to small pieces of the dyed 
cloth in a watch-glass bring out the following colors: Cochineal, 
purplish; cudbear, violet; amaranth, brown; ponceau 3 R, pink; 
erythrosin, pink; orange I, deep red; naphthol yellow S, yellow. 
Concentrated sulphuric acid added to other pieces develops the 
following colors: Cochineal, pink; cudbear, dirty color; Amar- 



138 SACCHARINE PRODUCTS 

anth, violet; ponceau 3R, cherry red; erythrosin, orange; 
orange I, magenta; naphthol yellow S, decolorized. 

The reactions thus obtained, although quite decisive for 
the small number of colors used in our samples, are not so sat- 
isfactory when the hundreds of possible colors are involved, 
especially when two or more colors are present in the same 
product. 

Some natural fruit colors and various vegetable dyestuffs 
impart to the cloth a dirty color which gives indistinct color 
reactions. In such cases it is well to dissolve the color from the 
cloth by boiling with dilute ammonia water and repeat the dyeing 
test with a smaller piece of wool. While the coal-tar colors and 
some of vegetable origin dye the second piece of wool, fruit 
colors do not. 

Sostegni and Carpentieri use a few drops of hydrochloric 
acid in place of the potassium bisulphate solution. 

■^^Robin's Test for Cochineal. Dilute 10 cc. of syrups i and 3 
with an equal volume of water, add a few drops of hydrochloric 
acid, and shake in a separatory funnel with 25 cc. of amyl 
alcohol. Cochineal imparts to the amyl alcohol a yellowish 
color. Draw off the aqueous liquid and shake the amyl alcohol 
solution with several portions of water until neutral. To a por- 
tion of the amyl alcohol extract in a test-tube add a few drops 
of uranium acetate solution, shaking after each drop. If cochi- 
neal is present, the reagent acquires a beautiful emerald green 
color. To another portion add ammonia water. Cochineal, 
after this addition, gives a violet coloration. 

Ammonia water added directly to the syrup colored with 
cochineal gives the violet coloration. The same reagent added 
to the syrups colored with cudbear or other lichen color becomes 
blue. 

Mathewson has devised special tests for coal-tar colors which 
often give decisive results when the foregoing simple tests fail. 



CHAPTER VII 
FATS AND OILS 

Constitution of Fats and Oils. Fats and fatty oils consist 
chiefly of glyceryl triesters (commonly known as glycerides) 
of saturated acids belonging to the fatty series and of related, 
unsaturated acids. Glycerol, the anhydride of which is the 
essential and characteristic constituent of all fatty molecules, 
is a trihydric alcohol. The acids combined with glycerol in 
edible fats and oils belong in three series as follows: (i) saturated 
acids (C„H2„02), (2) unsaturated acids with one double bond 
(C„H2n-202), and (3) unsaturated acids with two double bonds 
(C„H2„-402). By far the most important of these acids are 
stearic acid (Ci8H3 602) and palmitic acid (C16H32O2), belong- 
ing to the first series, and oleic acid (C18H34O2), belonging to 
the second series. The table on page 140 includes these and 
other acids occurring in edible fats and oils. 

Action of Oxidizing Agents and Halogens on Unsaturated 
Acids. The difference in the molecules of stearic acid, belong- 
ing to the saturated or fatty series, and oleic acid with the same 
number of carbon atoms, belonging to the unsaturated series 
with one double bond, is brought out by the following structural 
formulas : 

H H 

Stearic Acid: CH3-rCH2)7-C-C-(CH2)7-COOH. 

H H 
H H 

Oleic Acid: CH3-(CH2)7-C=C-(CH2)7-COOH. 

139 



140 



FATS AND OILS 



The double bond in the middle of the oleic acid chain should be 
noted. Because of this structure oleic acid, like other unsat- 
urated acids, is more readily oxidized than the corresponding 
saturated acid, and forms halogen compounds analogous to the 
saturated molecule of stearic acid, thus explaining the theory 
of the iodine number determination (p. 152). 

Acms OF Fats and Oils Used as Foods (LewkowitschO 



Acid. 



Saturated Acids CnH2nO. 

Butyric 

Caproic 

Caprylic 

Capric 

Laurie 

Myxistic 

Palmitic 

Stearic 

Arachidic 

Behenic 

Lignoceric 

Unsaturated Acids 

y^ntiin—vJ 

Hypogaeic 

Oleic 

Iso-oleic 

Rapic 

Erucic 

C«H2n-40 

Linolic 



Formula. 



C4H8O2 

CeHuO^ 

CsHieO^ 

CioH.oO., 

C12H240., 

CmHosO. 

C16H3202 
C18H3602 
C20W40U2 

C22H4402 



C16H30O2 
C1SH3402 
C18H3402 
C18H3402 
C22H4202 

C18H3202 



Occurrence. 



Butter 

Butter, cocoanut, palm nut 

Butter, cocoanut, palm nut 

Butter, cocoanut, palm nut 

Cocoanut, palm nut 

Cocoanut, sesame, palm nut, 

butter 
Most fats and oils 
Fats and most oils 
Peanut, butter^, rape, cocoa 
Rape, mustard 
Peanut 



Peanut 

Most fats and oils 

Rape, mustard 
Rape, mustard 

Linseed, olive, cotton seed, pea- 
nut, sesame, cocoa, poppy 
seed, sunflower. 



' Chemical Technology and Analysis of Oils, Fats and Waxes. 5th Ed. 
2 Trace. 

Saponification. Glycerides saponified by heating with con- 
centrated sulphuric acid or slaked lime yield glycerol and 
the organic acids by catalysis. When the saponification is 



CHEAIICAL AND PHYSICAL CONSTANTS 141 

effected by boiling with sodium or potassium hydroxide, alkali 
salts of the organic acids (soaps) and glycerol are obtained. In 
the determination of saponification number (p. 155), which is 
the number of milligrams of potassium hydroxide required to 
saponify one gram of fat, the result obtained is inversely pro- 
portional to the average molecular weight of the glycerides 
present. 

Solubility and Volatility of the Acids. Butyric acid is sol- 
uble in water and distills without decomposition with steam. 
As the number of atoms in the acid molecule increases the sol- 
ubility and volatihty decrease, the former, however, more 
rapidly than the latter. The methods of determining soluble 
acids and soluble and insoluble volatile fatty acids (Reichert- 
Meissl and Polenske numbers) in fats and oils are based on 
these properties of the component acids. 

Chemical and Physical Constants. In examining fats and 
oils with reference to their identity and purity complete analyses, 
involving determinations of the individual acids even if possible, 
would involve a vast amount of labor and be difficult to interpret. 
Instead of such analyses, determinations are made of the so- 
called " constants," dependent on the chemical and physical 
properties of the glycerides, or of the acids combined as glycer- 
ides. Owing to the somewhat variable amounts of the different 
glycerides in a given commercial fat or oil the constants vary 
within certain limits and are not, therefore, such definite figures, 
as for example, the melting- or boiling-point of a single pure 
glyceride. Allowance must always be made for this variation 
in deciding as to the identity or purity of a given fat or oil and 
especially in calculating the proportion of the constituents in a 
mixed fat from the results obtained in the determination of the 
constants. The following are the most important constants: 

Physical Constants: Specific gravity, refractive index, melting- 
point, solidifying-point, viscosity, rise of temperature with sul- 
phuric acid (Maumene test), heat of bromination. 

Chemical Constants: Iodine number (Hiibl or Hanus 
number), saponification number (Koettstorfer number), soluble 



142 FATS AND OILS 

volatile fatty acids (Reichert-Meissl number), insoluble volatile 
fatty acids (Polenske number), soluble fatty acids, insoluble 
fatty acids, bromine number, acetyl value, free fatty acids, 
unsaponifiable matter. 

All of the above constants are determined directly on the fat 
or oil; some of them, notably the solidifying-point (titer test), 
melting-point, and the iodine number, are also applicable to the 
mixed fatty acids obtained by saponification. 

The table on p. 143 gives the range in specific gravity, refrac- 
tive index, iodine number, saponification number, and volatile 
fatty acids of the most important edible fats and oils. Methods 
of determining the five constants selected, which are those most 
commonly determined, are described in the following sections. 
No figures are given for oleo oil, beef or cotton seed stearin, or 
the various mixtures used as butter and lard substitutes, as these 
are more or less indefinite in composition. 

■^^Material for Laboratory Practice. Most of the materials 
given in the table on p. 143 may be obtained of the grocer, the 
butcher, or the druggist; the remainder from dealers in labora- 
tory supphes. Butter fat is obtained from butter by melting 
and decanting off the clear fat onto a filter. A sample of oleo- 
margarine fat may be obtained in the same manner. Beef tallow 
may be rendered in the laboratory from suet; mutton tallow 
being of nearly the same composition may be dispensed with. 
So-called " compound lard," a lard substitute consisting of a 
mixture of cotton seed oil with enough beef or cotton seed 
stearin to harden it and a certain amount of real lard to impart 
flavor, should also be included. 

The source and method of manufacture of the dififerent fats 
and oils need not here be considered. Most of them are well- 
known products in the United States; sesame and rape oil, 
however, are less often met with. Sesame seed is extensively 
grown in India and other Oriental countries, where both the oil 
and the cake are important foods. Rape oil is obtained from the 
seeds of various species of the mustard family grown in Europe 
and the East. Cocoa butter, the fat expressed from cocoa mass 



TABLE OF CONSTANTS 



143 



or chocolate in the manufacture of cocoa, is hard and waxy, 
cocoanut oil, on the other hand, a very soft fat at ordinary tem- 
peratures and a liquid on hot days, is classed, as the name 
implies, with the oils. 

Constants of Edible Fats and Oils 
(As given by Lewkowitsch and others) 



specific 

Gravity at 

15-5° C. 



Refractive 
Index. 



Iodine 
Number. 


Saponifica- 
tion 
Number. 


79-88 3 


185-196 


104-110 


193-195 


83-103 


190-196 


103-115 


189-193 


94-105 


170-179 


8-9-5 


246-268 


26-38 


227 


35-47 


192-200 


32-46 


192-195 


47-70 


195 


32-41 


192-202 



Volatile 
Fatty 
Acids 

(Reichert- 
Meissl 

Number). 



Olive oil 

Cottonseed oil 
Peanut oil ... . 
Sesame oil. . . . 

Rape oil 

Cocoanut oil. . 
Butter fat . . , 
Beef tallow . . . 
Mutton tallow 

Lard 

Cocoa butter. . 



9I6-.9I8 




922-. 925 




9I7-.92I 




923-924 




9I3-.9I7 




912 




.926-. 940 




•943-- 952 




•937-- 953 




934-938 




950-.976 





4660-1 .4680 ' 

4700-1.4725 1 
4690-1.4707 1 
4704-1. 471 7' 
4710 1 



4590-1 
4586 2 
45862 
4584-1 
4566-1 



.4620' 



4601 2 

4578" 



0.6 
1 .0 

1 .2 
0.6 
7- 8.4 
25-30.4 
05 

I . I 

o . 2-0 8 



■At 25° C. 2 At 40° C. 

' European olive oil; California olive oil sometimes runs over 90. 

So far as possible each student should be assigned a different 
fat or oil for determinations of specific gravity, refractive index, 
iodine number, and saponification number, the last two being 
determined in duplicate. Each student should also make a 
single determination of volatile fatty acids on both butter fat 
and oleomargarine fat, also apply the Halphen test for cotton 
seed oil and the Baudouin test for sesame oil, both to the oils 
themselves and to pure olive oil and in the case of Halphen test 
to pure and compound lard. One laboratory period is sufficient 
for these qualitative tests and the determination of the two 
physical constants, and one day for the determination of each 
of the three chemical constants, assuming that the reagents and 
standard solutions are furnished ready for use. 



144 



FATS AND OILS 



The clieniical student doubtless will have already prepared 
and standardized sodium tliiosulphate solution and tenth- 
normal sodium or potassium hydroxide solution, in which case 
these solutions may be used for the determinations of the iodine 
number and volatile fattv acids. The standardizinsr of half- 




FiG. SS. — Westphal Balance. 



normal hydrochloric acid, required for the determination of the 
saponincation number, is described on p. 7c. 

*DetenniiLation of the Specific Gravity with the Westphal 
Balance. The construction and method of use of the balance 
aire e\'ident from Fig. SS. Instead of weights there are four 
sizes of riders corresponding, when hung at the end of the beam, 



SPECIFIC GRAVITY WITH THE WESTPHAL BALAN'CE 145 

to specific gravity readings of i, o.i, o.oi, and o.ooi, resp)ectively, 
and, when hung in the notches, to decimals of these readings as 
indicated by the numerals. In case two or more riders belong 
on the same notch the smaller should be suspended from one of 
the hooks of the larger. The thumbscrew at the base serves 
to bring the beam in exact equihbrium. as indicated by the points 
at the left, when the dr>' plummet is hung in the air. Distilled 
water at 15.5^ C, by the thermometer in the plummet, should 
show a specific gra\'ity of exactly i.ooo. The specific gravity 
of the liquid sliov/n in the cut is 1.1267, two of the largest size 
riders being used, one at the end and the other at i on the beam. 
The specific gravity of the oils (except cocoanut) should be 
taken within a few degrees of 15.5^ C. and the readings calcu- 
lated to that temperature by the formula: 

G =G"H-o.ooo64fr — 15.5), 

in which G is the specific gravity at 15.5^, G' the specific gravity 
at T°. Although the factor varies somewhat for the different 
oils the average (0.00064^ is sufliciently accurate if the tem- 
perature does not varv- greatly from 15.5°- 

The fats, also cocoanut oil which at ordinar}- temperatures 
is a soft fat, should first be melted in a tall beaker over a 
piece of asbestos, using a low flame. Keeping the temperature 
as near constant as possible and only slightly above the melting- 
point, determine the specific gravity and note at the same time 
the exact temperature. Care must be taken that the melted 
fat is kept thoroughly mixed and consequently of uniform tem- 
perature throughout during the observation. As the melting 
temperature of hard fats must var>' considerably from 15.5^, 
the factor peculiar to each fat must be used instead of 0.00064 
in calculating to the standard temperature as follows: 

Factors for Correcting Specific Gravity (.\llex) 

Butter fat o . 00061 7 

Tallow 000675 

Lard 000650 

Cocoa butter 000717 



146 



FATS AND OILS 



The specific gravity may also be determined in a pycnometer 
or by accurate spindles, but for practical work the Westphal 
balance is to be preferred. The temperature of boiling water, 
using a special heating apparatus, is often employed and the 
observed reading compared with the limits obtained on samples 
of known purity at that temperature. 




Fig. 89. — Zeiss Butyro-refractometer. 

^Determination of the Refractive Index. Two forms of 
refractometer both made by Carl Zeiss, Jena, are suitable for 
the examination of fats and oils. One of these, the butyro- 
refractometer (Fig. 89), has an arbitrary scale on which the 
degree of refraction is observed directly through the eyepiece, 
the other, the Abbe refractometer (Fig. 90), gives readings in 



REFRACTIVE INDEX 147 

terms of refractive index on the sector 5 after rotating the tele- 
scope F until the border line of total reflection passes through 
the point of intersection of two crossed Hnes. Both employ two 
Abbe prisms, A and B, on the lower one of which, when open 
(Fig. 89), a drop of the fat or oil is placed forming, when closed 
(Fig. 90), a thin film through which the light passes after being 




Fig. 90. — Abbe Refractometer. 

reflected upward from the mirror. Both also are arranged to 
permit the passage of a stream of water of constant temperature 
through the two prisms, the temperature being indicated by a 
delicate thermometer. 

The Abbe instrument, notwithstanding its more complicated 
construction and more cumbersome scale, is to be preferred for 



148 



FATS AND OILS 



general work, as it has a wider range, thus permitting its use for 
the examination of essential oils and the determination of the 
total solids of molasses, honey, and syrups from the refractive 
index. The scale reading obtained with one form of refractometer 
may be converted into the equivalent of the scale of the other 
form by calculation or reference to the table on p. 222. 




Fig. 91. — Zeiss Immersion Refractometer. 

A third form, known as the immersion refractometer (Fig. 91), 
used in the examination of milk serum, in the detection of 
methyl alcohol in liquors, etc., has a prism P, at the end of the 
tube which, for ordinary use, is plunged in a beaker containing 
the liquid under examination kept at a constant temperature in 
a glass-bottomed tank. At the left in Fig. 91, is shown a sec- 



ABBE REFRACTOMETER 149 

tion of the tube with a special metal beaker at the bottom 
for the examination of liquids excluded from the air. 

^Manipulation of the Abbe Instrument. Place the instru- 
ment in front of a window but not in the direct sunHght. Pro- 
vide a large tank elevated about 2 ft. above the desk with a 
suitable arrangement for heating the water and a cock or siphon 
connected with a rubber tube for conducting a slow stream of 
the warm water to the refractometer. The tank should be large 
enough to hold water sufficient for the group of students using 
it on the same day. Heat the water to 40° C. for the examina- 
tion of the more solid fats. Afterward water can be added and 
the temperature lowered to 25° C. for taking the readings on 
butter fat and the oils. The stream of water enters the lower 
prism (Fig. 90) at C, passes into the upper prism through the 
rubber tube and out of the latter at E. When the temperature, 
as shown by the thermometer in the upper prism, becomes con- 
stant release the lower prism by opening the screwhead v and 
allow it to swing into the position shown in Fig. 89. Smear a 
drop of the oil or melted fat on the glass surface, close, and again 
fasten in position with v. Rotate the tube with attached sector 
on the alidade until the border line appears in the field, then by 
means of the screwhead M, so adjust the compensator that the 
band of colors, due to dispersion, disappears and a sharp line 
of demarkation is obtained. Next rotate the tube until this 
Hne passes exactly through the intersection of the crossed lines 
of the instrument, making sure the temperature has become 
constant. Finally read the refractive index through lens L 
and record both this and the temperature. 

If the temperature varies from 40° or 25° (T), as the case 
may be, correct the reading R' a.t T' to a reading of R by the 
formula R=R' —0.000365 (T — T'). 

Leach and Lythgoe have devised a slide rule (Fig. 92), which 
not only converts the reading at one temperature to the reading 
at another, but also shows the butyro-refractometer readings 
corresponding to different refractive indices. 

The refractometer furnishes the simplest means of dis- 



150 



FATS AND OILS 



3-4 
3J 



i- ---n 



Ak 



Fig. 92. — Leach and Lythgoe 
Slide Rule for Refractom- 
eter Calculations. 



tinguishing olive oil, butter, and lard 
from imitations. The limits given in 
the table on p. 143 serve to distinguish 
olive oil from cotton seed and sesame 
oil. Wolny finds that the refractive 
index of the fat of pure butter at 
25° C. ranges from 1.4590 to 1.4620 
and of oleomargarine containing no real 
butter from 1.4650 to 1.4700. Lard, 
as given in the table on p. 143, has a 
refractive index at 40° C. of 1.4584 to 
1. 460 1, while compound lard as found 
by the author shows a range of from 
1.4606 to 1.4639. 

^Detection of Cotton Seed Oil by 
the Halphen Test. Olive oil was 
formerly extensively adulterated with 
cotton seed oil. Compound lard and 
other lard substitutes commonly con- 
sist largely of cotton seed oil and oleo- 
margarine often contains cotton seed 
oil in addition to other fats. 

The Halphen test ^ is carried out as 
follows: Place in a test-tube about 
5 cc. of the oil or melted fat and the 
same volume of Halphen reagent, con- 
sisting of a mixture of equal volumes 
of carbon bisulphide, containing in 
solution I per cent of sulphur, and 
amyl alcohol. Mix and heat in a bath 
of boiling saturated brine for fifteen 
minutes. If cotton seed oil is present 
a deep red color is formed. 

The constituent of the oil that gives 
the color, the identity of which has 
^Analyst, 1897, p. 326. 



SESAME OIL BY THE BAUDOUIN TEST 151 

not yet been established, is destroyed or driven off by heating 
at 2^ to 270° C. (Holde and Pelgry, Fulmer), but oil thu 
treated is not likely to be used. The amyl alcohol is useful 
because it contains pyridin (Gastaldi). ^ ^ ^ .- t. 

Another quahtative testis that first proposed by Bechi. It 
depends on the reduction of silver on heating the oil with a solu- 
tion of silver nitrate in a mixture of alcohol and ether acidulated 
with nitric acid. This test is not entirely satisfactory as rancid 
and overheated oils and fats not containing cotton seed oil often 
give a slight reduction. MiUiau obviates this difficulty by apply- 
ing the test to the fatty acids separated by saponification 

%Detection of Sesame Oil by the Baudouin Test. Sesame 
oil is used as a substitute for and adulterant of ohve oil. ^ The 
addition of a small amount of sesame oil to oleomargarine is 
required by the laws of certain European countries so that the 
food inspector will readily be able to distinguish the product 
from butter by means of a sunple quahtative test. 

Apply the Baudouin test^ to samples of oUve and sesame oil 

as follows: . 4. 4.^ a 

Dissolve 0.1 gram of cane sugar in 10 cc. of concentrated 
hydrochloric acid in a test-tube, add 20 cc. of the oil to be tested, 
and shake thoroughly for one minute. Allow to stand until he 
oil rises. If sesame oil is present to the amount of i per cent, the 
aqueous solution will become deep red. , , . f 

Certain pure African oUve oils are said to give a color,but o a 
different shade from that obtained with sesame oil. In doubtful 
cases the test may be applied to the fatty acids. 

The test depends on the reaction of a minor constituent of 
the oil with the furfural formed by the action of the acid on the 
sugar. ViUavecchia and Fabris^ employ an alcoholic solution 
of furfural instead of sugar. ^ 

Other Qualitative Tests. Tolman's modification of Renard s 
test for peanut oil,^ based on the separation of arachidic acid, is 

iZtschr. angew. Chem., 1892, p. SOQ- 

2 Jour. Soc. Chem. Ind., 1894, P- i3- 

3 U. S. Dept. Agr., Bur. Chem., Bui. 77- 



152 FATS AND OILS 

useful in the examination of olive oil. Palm oil used as a coloring 
for oleomargarine is detected by tests devised by Crampton and 
Simon. 1 Various tests are in use for detecting artificial colors, 
such as sulphur, annatto, carotin, and oil-soluble coal-tar dyes, 
in butter. Beef stearin, a common ingredient of lard substi- 
tutes, is detected by modifications of Belfield's microscopic test. 

^Determination of Iodine Number by the Hanus Modifica- 
tion of the Hiibl Method. The formation of halogen addition 
compounds of the glycerides of the unsaturated acids occurring 
in fats has already been noted (p. 140). The determination of 
the iodine number serves to measure the degree of unsaturation. 
Two factors, involving the constitution of the fat, influence the 
results, (i) the nature of the unsaturated acids present, those 
with two double bonds absorbing a greater percentage than 
those with the same number of carbon atoms but with only one 
double bond, and (2) the molecular weight of the glycerides, 
those with low molecular weights absorbing a greater per- 
centage than those of the same degree of saturation with 
high molecular weights. Of these factors the former is by far 
the most important. For example linseed oil has a very high 
iodine number (about 175), due to the presence of a considerable 
amount of linolic acid with two double bonds, while cocoanut 
oil, which consists largely of saturated acids, has a very low 
number (less than 10). 

The original method of determining iodine number devised 
by Hiibl, which for many years was exclusively used, employed 
a solution of iodine and mercuric chloride in 95 per cent alcohol. 
This solution deteriorated so rapidly in strength that after a 
few days it was useless, furthermore it acted so slowly on the 
fat that three hours' standing was required for the absorption of 
the iodine. Both of these defects are obviated by the solutions 
proposed by Hanus ^ and by Wijs, the former now being more 
generally used in the United States and the latter in England. 
The Wijs solution consists of iodine chloride dissolved in glacial 

1 Jour. Amer. Chem. Soc, 1905, 27, p. 270. 
^Ztschr. anal. Chem., 1901, 4, p. 913. 



IODINE NUMBER 153 

acetic acid. Hanus in his modification of the Wijs solution 
employs iodine bromide. 

Reagents: (i) Iodine Solution. Dissolve 13.2 grams of 
pure iodine in i liter of pure 99 per cent acetic acid and when 
the solution has cooled add 3 cc. of bromine. After the addition 
of the bromine the halogen content, as determined by titration 
against thiosulphate solution, should be nearly but not quite 
doubled. 

(2) Decinormal Sodium Thiosulphate Solution. Dissolve 
exactly 24.8 grams of the c. p. crystallized salt in water and make 
up to I liter in a graduated flask. Unless the salt is impure or 
moist, which has never happened in the author's experience, the 
solution will be of the proper strength and further standardizing 
will be merely confirmatory. 

The solution may be standardized by iodine, by potassium 
iodate, or by potassium bichromate. The iodine method, which 
is the oldest and in the author's experience the most accurate, is 
as follows: Tare a short glass tube, such as is used for weighing 
out the fat (Fig. 93), together with a microscopic cover glass; 
place in the tube about 0.2 gram of c. p. resublimed iodine, heat 
cautiously until the iodine melts, close with the cover glass, cool 
in a desiccator, and weigh. Dissolve the iodine in 15 cc. of 
10 per cent potassium iodide solution, dilute with water, and 
add thiosulphate solution from a burette with stirring until only 
a yellow color remains, then add a little starch paste and con- 
tinue the addition until the blue color is discharged. One cc. of 
the iodine solution should be equivalent to 0.0127 gram of iodine. 

(3) Starch Paste. Mix i gram of starch with 200 cc. of 
water, boil for ten minutes, and cool. 

(4) Potassium Iodide Solution. Dissolve 100 grams of the 
salt in water and make up to i liter. 

Manipulation. Weigh a flat-bottomed glass cylinder about 
10 mm. in diameter and 15 mm. high (Fig. 93). Transfer to 
the cylinder by means of a glass tube from 0.15 to i.o gram of 
the oil or melted fat, the quantity used being such as to absorb 
not more than 40 per cent of the iodine present in 30 cc. of the 



154 



FATS AND OILS 



iodine solution. Use about (but no more than) 0.15 gram of 
olive, cotton seed, peanut, sesame, or rape oil, 0.25 gram of lard, 
0.3 gram of beef or mutton tallow, 0.4 gram of butter fat or 
cocoa butter, and i .0 gram of cocoanut oil. Weigh the cyhnder 

containing the oil or fat, in 
the latter case after cooling to 
room temperature. Because 
of the small quantities em- 
ployed the weighing of the 
cylinder, both before and 
after adding the material, 
should be performed with the 
highest degree of accuracy 
which is possible because of 
the small size of the cylin- 
ders and the non-hygroscopic 
character of the fatty ma- 
terials. No desiccator need 
be used. 

By means of a pair of for- 
ceps carefully introduce the 
cylinder and contents into 
a glass-stoppered bottle of 
about 300-cc. capacity, add 
10 cc. of chloroform and, after 
complete solution is effected, 
introduce 30 cc. of the iodine solution with great care by 
means of a pipette. Shake gently and allow to stand in a 
dark place with occasional shaking for thirty minutes. 

Add 15 cc. of potassium iodide solution and 100 cc. of water, 
then titrate slowly with standard thiosulphate solution, depend- 
ing for an indicator first on the yellow color of the Hquid and 
finally, when that has nearly disappeared, on the blue color 
obtained by adding a little starch paste. When the titration 
is nearly finished, stopper the bottle after each addition of 
thiosulphate, and shake to remove the iodine from the chloro- 




FiG. 93. — Iodine Number Apparatus. In- 
troducing cylinder with fat into bottle. 
Cylinder natural size at right. 



SAPONIFICATION NUMBER 155 

form. In addition to duplicate analyses two blank determina- 
tions should be performed in exactly the same manner, using 
only the reagents. 

In calculating the results subtract from the average number 
of cubic centimeters of thiosulphate solution, obtained in closely 
agreeing blank determinations, the number of cubic centimeters 
obtained in each actual analysis, and multiply the difference by 
0.0127, thus obtaining the grams of iodine absorbed. To obtain 
the percentage of iodine absorbed, which is the iodine number, 
multiply the grams of iodine absorbed by 100 and divide by the 
weight of material employed. 

^Determination of the Saponification Number by the Koetts- 
torfer Method. This number ^ is a measure of the average 
molecular weight of the mixed glycerides constituting a given 
fat or oil. Although the range is not nearly so great as that of 
the iodine number, the saponification number is an important 
constant, particularly in distinguishing rape, mustard, and other 
cruciferous oils from most of the other edible oils, in identifying 
cocoanut oil, and in an exhaustive examination of butter sus- 
pected of sophistication. 

Reagents, (i) Alcoholic Potassium Hydroxide Solution. Dis- 
solve 30 grams of c. p. potassium hydroxide in i liter of 95 per 
cent alcohol, previously purified by standing some days with 
potassium hydroxide and distillation. The solution is approx- 
imately half-normal. 

(2) Standard Half-Normal Hydrochloric Acid Solution. — 
Prepare in the usual manner and standardize as described on 
p. 70. 

Process. Weigh accurately an Erlenmeyer flask of about 
200-cc. capacity, introduce 2 to 2.5 grams of the oil or melted 
fat (1.5 to 2 grams of butter or cocoanut fat), and weigh again. 
Add 25 cc. of the alcoholic potassium hydroxide solution, con- 
nect with a reflux condenser, and boil gently, by heating over a 
piece of asbestos paper, for thirty minutes (Fig. 94). Cool, add 
a few drops of phenolphthalein solution as an indicator, and 
'Ztschr. anal. Chem., 1879, p. 199. 



156 



FATS AND OILS 



titrate the excess of alkali with standard half-nonnal acid solu- 
tion. 

Conduct two actual analyses, then two blanks in exactly 

the same manner. It is 
immaterial whether the 
quantity of potash solu- 
tion discharged from the 
pipette is exactly 25 cc, 
but of great importance 
that the quantity is the 
same in all cases. Care 
must, therefore, be taken 
to use the same pipette 
and allow it always to 
drain for exactly the same 
length of time. 

In calculating the re- 
sults subtract from the 
average number of cubic 
centimeters of half-nor- 
mal acid, obtained in 
closely agreeing dupli- 
cates, the number ob- 
tained in each actual 
analysis, multiply the re- 
sult by 28.06 (the number 
of milligrams of KOH 
corresponding to each 
cubic centimeter of half- 
normal acid), and divide 
the product by the 
weight of material em- 
ployed. The Koettstorfer or saponification number thus cal- 
culated represents the number of milligrams of potassium 
hydroxide necessary to saponify completely i gram of the 
material. 




Fig. 94. — Saponification Number Apparatus. 



VOLATILE FATTY ACIDS 



157 



^Determination of the Volatile Fatty Acids by the Leffmann 
and Beam Modification ^ of the Reichert-Meissl Method. 

This process is used chiefly in distinguishing oleomargarine from 
butter. It depends on the presence in butter fat of a consid- 
erable amount of glycerides of the fatty series with low carbon 
content, notably butyric acid (C4HSO2), whereas the fats and 
oils used in butter substitutes, known collectively as oleomar- 
garine, contain only small amounts if any. These acids are 
volatile on distillation with steam and are also quite soluble in 
water. Reichert was the first to make use of these facts in a 
method for detecting oleomargarine. The process was later 
improved by Meissl and later still by Leffmann and Beam, the 
latter employing for saponification a mixture of glycerol and 
sodium hydroxide instead of alcoholic sodium hydroxide solution. 
Polenske,^ in 1904, further modified the process so as to 
determine the volatile acids insoluble, as well as those soluble, 
in water, thus differentiating cocoanut oil, which contains a 
considerable amount of glycerides of these insoluble volatile 
acids, from butter. The following figures illustrate the value 
of both determinations: 



Butter fat, 31 samples, (Polenske). 
Cocoanut oil, 4 samples (Polenske) 

Oleomargarine fat (Arnold) 

Lard (Arnold) 

Tallow (Arnold) 



Reichert-Meissl 
Number. 



23 ■ 3-30 ■ I 

6.8- 7.7 

0-3S 
0.55 



Polenske 

Number. 



i-s- 30 

16. 8-17. 8 
0-S3 
o-S 
0.56 



By referring to the table on p. 140, it will be noted that 
butter contains acids with four to fourteen atoms of carbon and 
cocoanut oil, acids with six to fourteen atoms, both inclusive. 
It should be further noted that butter fat contains a consider- 
able amount of the acid with four atoms of carbon (butyric), 

^ Analyst, 1891, p. 153. 

2 Arbeit a. d. Kaiserl. Gesundheitsamte, 1904, p. 545. 



158 



FATS AND OILS 



which is not found in cocoanut oil, while cocoanut oil contains 
considerable amounts of acids with twelve and fourteen atoms 
(lauric and myristic) which occur only in small quantities in 
butter fat. Since the solubility decreases as the number of 
carbon atoms increases, it is obvious why butter fat gives a 

high Reichert-Meissl 
number and cocoanut oil 
a high Polenske number 
As cocoanut oil is not 
so commonly used in 
American oleomargarine 
as that made in Europe, 
only the soluble volatile 
acids or the Reichert- 
Meissl number need be 
determined by the stu- 
dent. Single determina- 
tions should be made on 
both butter fat and oleo- 
margarine fat prepared 
as described on p. 142. 

Method. Weigh accu- 
rately a 300-cc. Jena 
flask, introduce as much 
of the melted fat as will 
be delivered by a clean, 
dry 5-cc. pipette, and 
enough more to bring the 
weight up to about 5 
grams. Allow to cool and 
weigh accurately flask and 
fat. Add 20 cc. of glycerine and 2 cc. of a solution prepared by 
dissolving 100 grams of c. p. sodium hydroxide, free from carbon- 
ates, in 100 cc. of boiled water. Heat cautiously on a piece of 
asbestos paper until the fat is saponified, which requires about 
five minutes and is indicated by the clearing up of the boiling 




Fig. 95.- 



-Distillation Apparatus for Volatile 
Fatty Acids. 



POLENSKE NUMBER 159 

liquid. While still hot add very cautiously, at first, drop by 
drop, to prevent foaming, 90 cc. of boiled water and shake 
until the soap is dissolved. The solution should be perfectly 
clear and nearly colorless. Rancid or oxidized fats that yield 
a brown soap should not be examined. 

To the soap solution add 50 cc. of dilute sulphuric acid (25 cc. 
to I liter), and about 0.5 gram of granulated pumice stone with 
grains i mm. in diameter, then connect with a condenser, such 
as shown in Fig. 95, and distill at a rate sufficient to give a dis- 
tillate of no cc. in about twenty minutes, using a stream of 
water that will cool the condensed liquid to about 20° to 30°. 
Cool in water of about 15°, make up to the mark, mix by invert- 
ing the flask four or five times, filter through an 8-cm. dry filter, 
and pipette 100 cc. of the filtrate into a beaker. Titrate with 
tenth-normal alkali, using a few drops of phenolphthalein solu- 
tion as an indicator. 

If exactly 5 grams of fat were used the number of cubic centi- 
meters of standard alkali required multiplied by i.i is the 
Reichert-Meissl number, otherwise calculate to that amount. 

Determination of the Polenske Number. In this determina- 
tion (which for reasons already stated may be omitted), the 
condenser tube, flask, and filter, after obtaining the Reichert- 
Meissl number, as described in the preceding section, are washed 
with three 15-cc. portions of water and the insoluble volatile 
acids dissolved by the same treatment, using 15-cc. portions 
of neutral 90 per cent alcohol. The united alcohoUc washings 
are finally titrated as in the determinations of the soluble acids. 

Other Constants of Fats and Oils. The Melting-point of 
Fats ^ is determined in a capillary tube similar to that used for 
crystalHne substances except that it is open at both ends, the 
melted fat being drawn up into the tube and allowed to soUdify 
(Fig. 96). After twelve hours' cooling the tube is attached by 
a rubber band to the bulb of a delicate thermometer and both 
are suspended in a test-tube of water supported in a flask also 
containing water (Fig. 96). 

1 Leach's Food Inspection and Analysis, p. 480. 



160 



FATS AND OILS 



The flask is gradually heated until the fat melts. 
The Maumene Test ^ is the measure of the rise of heat with 
sulphuric acid, which is highest with oils containing the greater 

percentages of unsaturated acids 
and, therefore, having the highest 
iodine numbers. 

The Bromination Test is similar 
to the last in principle, bromine 
being used instead of sulphuric acid. 
Another physical test is the 
solidifying point of the fatty acids, 
known as the Titer Test, determined 
by the Dalican method. 

Most of the tests designed 
primarily for the oils or fats them- 
selves may also be determined on 
the fatty acids liberated by a min- 
eral acid after saponification. Nat- 
urally the results are not the same 
as those obtained by the direct 
determination. 

Among the chemical tests is the 
estimation of the Soluble and In- 
soluble Fatty Acids. In the method for the determination of 
the Reichert-Meissl number the separation of the insoluble 
acids as an oily liquid, after addition of sulphuric acid to the 
saponified fat, is evident. The method for determining the 
soluble and insoluble acids also involves saponification and sep- 
aration of the acids with a mineral acid. The soluble acids are 
determined by titration; the insoluble acids by direct weighing 
of the washed and cooled oily layer. The method is now of 
comparatively small importance. 

The method for estimating the Acetyl Value, first proposed 
by Benedict and later modified by Lewkowitsch, depends on the 
substitution of the hydrogen of the alcoholic hydroxyl group 

' Comptes rendus, 1852, 35, p. 572. 




Fig. 96. — Melting-point Appa- 
ratus for Fats. 



HYDROGENATION OF OILS 161 

by the acetic acid radicle on heating with acetic anhydride, 
the acetylated fat being subsequently saponified and the acetic 
acid separated and titrated. 

Fats and oils contain, in addition to glycerides, very small 
amounts of U nsaponifiable Matter such as Cholesterol and Si- 
tosterol. The former is found m animal, the latter in vegetable 
fats. 

Hydrogenation of Oils. The hardening of the oils by hydro- 
genation, using nickel or some other metalHc catalyzer, is now- 
practiced on a commercial scale, cotton seed and other vege- 
table oils being thus changed into hard fats by the conversion 
of the olein into a saturated glyceride such as stearin. This 
treatment takes the place of adding to oils a hard fat such as 
stearin for the purpose of imitating the consistency of lard and 
other semisolid fats. It also adds to the list of edible oils, whale 
oil, which is not only hardened, but freed from rank-tasting 
impurities. This process changes materially the constants of 
the oil, thus increasing greatly the difficulties in interpreting the 
results of analvses. 



CHAPTER VIII 
FRUITS, FRUIT PRODUCTS, LIQUORS, AND VINEGAR 

In ascertaining the food value of fruits and vegetables, as 
well as their products, the percentages of water, fat, fiber, pro- 
tein, ash, and nitrogen-free extract, determined by practically 
the same methods as are used for grain, seeds, and their products, 
are of first importance. 

Sugars. Determmations of sugars are of special value in the 
examination of fruits as sucrose and invert sugar, the former 
being largely transformed into the latter during ripening, are 
usually present, contributing to the immediate food value and 
furnishing the material for alcohoUc fermentation of the fruit 
juices in the manufacture of wines and ciders and for the subse- 
quent acetous fermentation in the manufacture of vinegar. 
Sweetened fruit products, such as preserves, jeUies, and fruit 
syrups, contain sucrose and invert sugar as their chief constit- 
uents, which are determined by the same methods as are used 
in the analyses of sugar, molasses, and other cane and beet 

products. 

Acids. As all succulent fruits contain one or more organic 
acids, such as malic, citric, and tartaric, which, in the case of 
vinegars, are supplemented by acetic acid, no analysis of a 
fruit product is complete that does not include the amount of 
acidity. Estimating this acidity by titration with a standard 
alkali solution does not differentiate between the different acids, 
although, in many cases, the chemist knows the acid present in 
a given product to the practical exclusion of all others, thus 
permitting the use of the proper factor for the calculation of the 
percentage of that acid from the volume of standard alkali 
solution employed. For example, the acidity of vinegar would 

163 



164 FRUIT PRODUCTS, LIQUORS, AND VINEGAR 

be calculated as acetic, disregarding the small amount of malic 
acid in cider vinegar and of tartaric acid or cream of tartar in 
wine vinegar, and the acidity of lime juice would be calculated 
as citric acid. 

Starch, Oil, and Fiber. A few fruits, notably the Danana, 
are distinctly starchy, although at full maturity the starch 
passes largely into sugar, and one common fruit, the olive, is very 
oily. Most fruits, however, contain only small amounts of 
these constituents. Fruit juices are not only free from starch 
and oil, but also from crude fiber, therefore the analysis of the 
juices and of the liquors and vinegars made from them would 
not include determinations of these three constituents. 

Alcohol and Other Constituents. The labor saved in omitting 
analyses for starch, oil, and fiber in liquid products is offset by 
the need of determining alcohol in alcoholic liquors and acidity 
in most fruit products as well as of a number of substances 
present in small amount in liquors and vinegars which, although 
of little or no food value, serve as indications of strength and 
purity. The calculation of the alcoholic strength of liquors 
from the specific gravity of the distillate is of great value in 
industrial work and in the enforcement of excise and adulteration 
laws. 

Solids. While in dry products such as flour, meal, and cattle 
foods there is no ocular indication of the presence of moisture, in 
liquid fruit products there is no appearance of solid matter. We 
accordingly give the results in the former case in terms of mois- 
ture, in the latter in terms of total solids or extract. In juices the 
extract consists largely of sugar, which disappears almost en- 
tirely on fermentation. 

"^Laboratory Practice. The purpose of the two laboratory 
exercises which follow is partly to aid the student in a practical 
understanding of a few important analytical processes and 
partly to show how these processes are applied in scientific and 
technical investigations, having in mind the formation of alcohol 
from sugars and of acetic acid from alcohol with the consequent 
disappearance of most of the solid matter. 



PRACTICE MATERIAL 



165 



Material for Practice. As representative fruit juices either 
sweet cider or grape juice may be selected, both products being 
obtainable bottled and sterilized. Fermented cider sampled 
after the escape of carbon dioxide has ceased or an unsweetened 
wine, such as claret, will serve as a suitable alcoholic beverage, 
and either cider or wine vinegar as an acetified liquid. The 
most interesting sets of samples are those made from the same 
lot of apple or grape juice, the sterilized juice, the cider or wine, 
and the vinegar being bottled at the suitable time. Lacking 
these the ordinary commercial products will answer. It is 
recommended that products of the same fruit, either apple or 
grape, be analyzed by the same student. In most sections of 
the United States the apple series will be most readily obtainable 
and the three products can be kept in bottles for years. 

The student should carry on determinations of solids and 
acidity, also tests for sugar, in the three products of the series, 
on the first day. On the second day he can give his attention 
largely to the determination of alcohol. All the results should 
be calculated as grams per loo cc, which is approximately the 
same as grams per loo grams or true percentage by weight. 

The average of several analyses of each of the three products 
follows: 



Average Composition of Apple Juice, Fermented Cider, 
AND Cider Vinegar 





.dumber 

of 
Analy- 
ses 
Aver- 
aged. 


Solids. 


Total 
Sugar 

as 
Invert. 


Malic 
Acid. 


Acetic 
Acid. 


Alcohol. 


Ash. 


Apple juice (Browne) . . 
Fermented cider 

(Browne) 


lO 

4 

22 


13.21 

2.46 
2.49 


11.72 

0.40 
0.25 


0.73 

0.25 
0. II 


0.34 
4.84 


5-40 


0.28 
0.26 


Cider Vinegar (Lythgoe) 


0.34 



166 FRUIT PRODUCTS, LIQUORS, AND VINEGAR 

Fruit Juices 

^Determination of Total Solids. The determinations of 
chief importance are of sohds, sugars, and acidity. As the solids 
consist largely of sugars, fruit juices may be regarded as dilute 
sugar syrups and the solids may be approximately estimated 
from the specific gravity or the refraction, using certain tables 
which have been prepared for the purpose. These methods 
have the advantage of rapidity, and the inaccuracy, due to the 
presence of solids other than sugar such as organic acids, is 
offset by the inaccuracies of a gravimetric determination due 
to the difficulty of removing all the water on the one hand and 
the decomposition of levulose during heating on the other. This 
latter error is obviated by drying in vacuo at 70° C, but the 
process is tedious and requires special apparatus. For many 
purposes drying in an open dish at 100° for a conventional time 
is satisfactory, the decomposition not being sufficient to affect 
the general conclusions. 

In this connection it may be stated that a method may not 
have the highest degree of scientific accuracy and yet be quite as 
useful for certain purposes as if it were absolutely exact. This 
is because it is often the relative rather than the absolute results 
that are desired, and also because by experience the analyst 
learns to interpret his analyses in terms of yield of alcohol or 
acetic acid by the commercial process. 

Method. Weigh a flat-bottom tinned lead or aluminum dish 
such as is used in determining milk sohds (p. 15), introduce 
5 cc. of the juice measured from a pipette, evaporate on a water 
bath to dryness, making sure that the liquid is distributed over 
the bottom of the dish, and dry in a water oven at the temper- 
ature of boiling water for two and one-half hours. Cool in a 
desiccator and weigh. All this can be done in a single labor- 
atory period. Calculate the weight of sohds in 100 cc. of the 
juice. If drying dishes or oven capacity are insufficient for 
duplicate determinations, one will answer. The process is so 
simple that errors of manipulation are not probable, further- 



SUGAR IN FRUIT JUICES 167 

more the results of the diflferent students should check each 
other. 

Carry along determinations on the fermented cider and 
vinegar by the same method and at the same time. 

■^Determination of Sugar. The sugar in a fruit juice freshly 
expressed is usually a mixture of sucrose and invert sugar, the 
latter being formed from the former during ripening. Further 
change of the sucrose to invert sugar goes on in the juice during 
storage and is accelerated during sterilization, consequently 
the sugar in the samples of sweet cider and grape juice used for 
laboratory practice, especially if sterilized, may consist entirely 
of invert sugar. In order to be certain of complete inversion, 
treatment with acid is necessary preliminary to copper reduc- 
tion, but for our purpose it will be sufi&cient to boil for two 
minutes i cc. of the fruit juice directly with 50 cc. of water 
and 25 cc. each of copper sulphate and alkaline Rochelle salts 
solutions (p. 76), noting that a copious precipitate of copper 
suboxide is formed. 

Should the student have opportunity the quantitative 
determination may be carried out as follows: 

Method. Pipette 5 cc. of the cider or grape juice into a loo-cc. 
graduated flask, dilute with about 50 cc. of water, and add lead 
subacetate solution (p. 133), drop by drop, until with shaking a 
precipitate no longer forms. Dilute to the mark, shake, and 
filter through a dry filter into an Erlenmeyer flask. To the 
filtrate add dry powdered potassium oxalate with shaking until 
all the lead is precipitated. Filter through a dry filter into a 
small Erlenmeyer flask. Pipette 50 cc. of the filtrate and 25 
cc. of water into a graduated loo-cc. flask, add 5 cc. of concen- 
trated hydrochloric acid, and invert in a water bath kept at 
72° to 73°, exactly as described on p. 131. Cool, add sodium 
hydroxide solution until shghtly alkaline to litmus paper, then 
add hydrochloric acid drop by drop until the paper turns red, 
make up to the mark, and shake. If the solution is not 
entirely clear, filter through a dry filter. 

Determine the copper-reducing power of 50 cc. of the solu- 



168 FRUIT PRODUCTS, LIQUORS, AND VINEGAR 

tion by the Munson and Walker method as described on p. 76, 
except that the weight of invert sugar, corresponding to the 
copper suboxide, should be found in the table (pp. 213 to 221), 
and the weight of this sugar in 100 cc. of the original cider or 
juice calculated. A comparison should be made of the results 
obtained for solids and sugars. 

^Determination of Acidity. Of the non-sugar solids, organic 
acids and ash are the chief constituents. Determine the acidit}' 
by titrating 25 cc. of the cider or juice with tenth-normal sodium 
hydroxide solution. For the cider use as indicator a few drops 
of phenolphthalein solution (i gram in 100 cc. of alcohol), for 
the grape juice, so-called neutral litmus paper. Titrate also 
the fermented cider or wine and the vinegar at the same time, 
using for the vinegar only 10 cc. 

Wine, Cider, and Other Liquors 

Fermentation. Grape must, cider, and other fruit juices 
ferment through the action on the invert sugar of the enzyme 
Zymase of the wild yeast plants Saccharomyces ellipsoideus, S. 
apiculatus, etc., which naturally occur on the outside of the 
fruit and find their way into the expressed fruit juices, the 
reaction being as follows: 

C6Hi206 = 2C2H60-F2C02. 

Dextrose or Alcohol Carbon 

levulose dioxide 

In the manufacture of malt liquors the conversion of starch into 
the soluble carbohydrate Maltose is first effected by means of 
Diastase, the enzyme of malt, then the maltose is hydrolized by 
means of an enzyme in yeast, known as Maltase or maltoglucase, 
with the formation of dextrose as follows : 



2C6Hio05+H20 = Cl2H220ll 

Starch Maltose 

C12H22O11 +H2O = 2C6H12O6. 

Maltose Dextrose 



FERMENTATION 169 

For the fermentation of malt liquors yeast of the species 
Saccharomyces cerevisicE is added. In making lager beer a strain 
known as bottom yeast (Fig. 97) is used while for ale top yeast 
(Fig. 98) is necessary. 

Liebig regarded fermentation as a purely chemical process 





Fig. 97,. — Bottom or Beer Yeast. Budding plants. (Lindner.) 

and ignored the biological theories of Pasteur and others 
which have since been accepted. Krober by his classical 
researches has more recently shown that the ferments of yeast 
may act without the intervention of the growth of the cells, 





Fig. 98. — Top, Ale, or Distillery Yeast. Budding plants. (Lindner.) 

thus returning in a sense to the purely chemical theories of 
Liebig. 

The carbon dioxide formed during fermentation is either 
allowed to escape or else, as in the case of malt liquors and 



170 FRUIT PRODUCTS, LIQUORS, AND VINEGAR 

effervescent wines, is confined, at least in part, by tight casks or 
corked bottles. 

Natural wines cannot contain more than i8 per cent of alco- 
hol, as the yeast plant ceases to grow after that strength has 
been reached. By adding alcohol, fortified wines, such as sherry 
and port, are obtained and by distillation any desired alcoholic 
strength can be secured. Cognac or French brandy is the 
distillate from wine, cider brandy, from fermented cider, whiskey 
and gin, from fermented grain infusions, and rum, from diluted 
and fermented molasses. 

Theoretically over 51 per cent of invert sugar is obtainable 
as alcohol, but practically under the most favorable conditions 
the yield is less than 49 per cent, the remainder going to form 
glycerol, succinic acid, and various higher alcohols which make 
up the fusel oil of distilled liquors. 

Analysis of Liquors. In addition to alcohol, the character- 
istic constituent of all fermented and distilled liquors, the fol- 
lowing minor constituents are determined: 

Wines and Ciders. Extract or sohds, sugars, acids (fixed and 
volatile), tartaric and malic acids (free and combined), glycerol, 
potassium sulphate (used in plastered wines), sodium chloride, 
nitrates, tannin, preservatives, and colors. 

Malt Liquors. Extract, sugars, dextrin, glycerol, acids 
(fixed and volatile), protein, phosphoric acid, added bitter 
principles and preservatives, and arsenic (introduced in glucose 
made with impure acid). 

Distilled Liquors. Extract, acids, esters, aldehydes, fur- 
fural, fusel oil, added wood alcohol, and caramel (added for 
coloring) . 

The complete analysis of a liquor is a laborious task, 
but such an analysis is not ordinarily necessary except in 
special cases as in detecting adulteration, in tracing the 
cause of certain defects, or as a guide in special manufacturing 
problems. 

The Composition of the most important wines, malt liquors, 
and distilled hquors appears in the following tables: 



COMPOSITION OF WINE AND OTHER LIOUORS 



171 



Average Composition of European Wines (Koenig) 
Results expressed as grams per loo cc. 





Alcohol. 


Extract. 


Total 
Acidity 

as 
Tartaric. 


Volatile 
Acids 

as 
Acetic. 


Sugar. 


Gly- 
cerol. 


Ash. 


Phos- 
phoric 
Acid. 


Claret. 


8.16 
8.12 

9.48 

16.09 
10.42 


2.42 
2.91 

3 03 

4.06 
2.36 


0.58 
0.77 
0.66 
0.41 
0.61 


0. 10 
0.05 
0.09 


0.23 
0.23 
0.84 
2.40 
053 


0-73 
0.8s 
0.97 

0.71 


0.25 
0. 20 
0.25 
0.46 
0. 14 


0.029 
0.045 
0.032 
0.028 


Rhine wine 

Sauterne 

Sherry 

Champagne (dry) 



Average Composition of Malt Liquors (Koenig) 





Alcohol 

by 
Weight. 


Extract. 


Acid 

as 
Lactic. 


Gly- 
cerol. 


Ash. 


Phos- 
phoric 
Acid. 


Nitro- 
genous 

Sub- 
stances. 


Sugar 

as 

Maltose. 


Lager beer 

Bock beer 

Ale 

Porter 


3-93 
4.69 

4-75 
4.70 


5-79 
7. 21 
5.6s 
6-59 


015 
0.17 
0.28 
0.28 


0.17 
0.18 


0.23 
0.26 
0.31 
0.36 


0.077 
0.089 
0.086 
0.093 


0.71 

0-73 
0.61 
0.65 


0.88 
I. 81 
I .07 
2.62 



Composition of Distilled Liquors 



Whiskey : 

Scotch, 8 yrs. old. . 
Irish, 7 yrs. old . . . 
Rye, 4 yrs. old .... 

Bourbon, 4 yrs. old 
Imitation rye 

Cognac, 10 yrs. old. . 

Rum 

Gin 

Neutral spirits 



Analyst. 



vasey 
Vasey 
Crampton 
and 
Tolman 
Ladd 
Vasey 
Vasey 
Vasey 
Ladd 



ftoJ 
< 



Grams per 100 Liters of Proof Spirits. 



185.0 



151-9 
S06 . 1 1 



Acids. 



6S 



S8 



7J 

37-2 

14.0 

0.0 

3.8 



44.8 
5 
69 -3 

53-5 

5-7 

54-6 

199.5 

18.7 

14.0 



5.6 
13.9 

II .0 
trace 
8.3 
4.2 
o.g 

3-2 



100. o 
102.0 
125.1 

123.9 
46.9 
62. 1 
45.3 
22.3 
14.8 



' Includes caramel color. 



172 



FRUIT PRODUCTS, LIQUORS, AND VINEGAR 



■^Determination of Alcohol. The method of determination is 
the same for all kinds of alcoholic liquors except that the addi- 
tion of O.I to O.I 2 gram of 
calcium carbonate or 
standard alkali to neutral 
reaction is necessary if the 
wine or cider has partly 
turned into vinegar and 
only 25 grams or cc. of 
distilled liquors and cor- 
dials are employed. 

Method. The distilla- 
tion apparatus used for de- 
termining the volatile fatty 




II 




Fig. 99. Fig. 100. 

Fig. 99.-=—/ Pycnometer; // Delivery Tube. 
Fig. 100. — Alcohol Distillation Apparatus. 

acids (Fig. 95) is suitable except that a delicate pycnometer 
(Fig. 99, /), is substituted for the wide-mouthed receiving flask 
and the condenser tube is connected at the lower end by means 



ALCOHOL IN LIQUORS 173 

of a rubber tubing with a delivery tube (Fig. 99, 77), the lower 
part of which is of such a size that it readily passes through 
the neck of the pycnometer. The height of the pycnometer 
should be such that it can stand erect on the balance pan and 
the inside of the neck should be 5 mm. It is calibrated to 
contain 100 grams of water at 15.5° C. Fig. 100 shows the 
complete apparatus for alcohol determination set up ready for use. 

If the liquor is effervescent pour from one glass to another 
until no more bubbles of carbon dioxide escape. Weigh the 
clean, dry pycnometer, introduce the delivery tube, and attach 
the latter to the condenser tube. Pipette 100 cc. of the sample 
into a 300-cc. flask, add 50 cc. of water and a little tannic acid to 
prevent frothing. Attach to the condenser, turn on the water, 
heat cautiously to boiling, and continue to boil until the pyc- 
nometer is filled nearly to the bottom of the neck. Detach the 
delivery tube, rinse with a few drops of water, and mix by shak- 
ing. Add water nearly to the graduation mark and place in a 
bath of water at 15.5°, taking care that the water covers the 
pycnometer to the height of the liquid within. After standing 
in the bath at least fifteen minutes, remove the pycnometer, 
without delay add water at 15.5° by means of a small pipette 
until the lower meniscus is exactly at the mark, dry off the out- 
side surface, and weigh. 

Subtract from the total weight the weight of the empty pyc- 
nometer, thus obtaining the weight of the distillate, which 
divided by 100 gives its specific gravity. In the table on pp. 
226 to 230 find the grams of alcohol per 100 cc. corresponding 
to the specific gravity, which is the common way of expressing 
the result in wine analysis, also the percentage of alcohol by vol- 
ume and by weight in the distillate. As the volume of the 
sample and of the distillate are both 100 cc, the grams of alcohol 
per 100 cc. and the percentage by volume in both are the same. 
To obtain the percentage by weight multiply the weight of the 
distillate by the percentage of alcohol by weight contained in it 
and divide by the weight of the sample obtained either by a 
direct weighing of 100 cc. or from the specific gravity. 



174 FRUIT PRODUCTS, LIQUORS, AND VINEGAR 

^Determination of Solids (Extract). As is true of fruit 
juices the extract in sweet wines (sherry, port, etc.), cannot be 
determined with absolute accuracy by drying at ioo°, owing to 
the decomposition of levulose. In the case of claret, Rhine wine, 
and others containing less than 3 per cent of extract, 50 cc. may 
be evaporated to dryness in a fiat-bottomed dish 85 mm. in 
diameter and dried for two and one-half hours at 100° C, as 
prescribed by the German ofl&cial method. 

In the analysis of the fermented cider or light wines selected 
for laboratory practice satisfactory results may be obtained by 
evaporating ic cc. of the wine or cider in a tinned lead or alum- 
inum dish 65 mm. in diameter, such as is used for milk soHds, and 
drying two and one-half hours at 100° C. This work is carried 
out in connection with the determination of solids in the juice 
and the vinegar. 

"^Determination of Acidity. Total acidity is found by the 
same method as is used for sweet cider or grape juice and vinegar. 

Volatile Acidity is valuable in wine analysis, as it is a measure 
of souring or incipient acetous fermentation. The process con- 
sists simply in distilling a portion of the wine and titrating the 
distillate. This need not be carried out by the student. 

Vinegar 

Kinds of Vinegar. Any alcoholic liquor of suitable dilution 
may be subjected to acetous fermentation for the manufacture 
of vinegar. On the Continent Wine Vinegar is commonly made 
from white or red wine, the former being the better. In Eng- 
land Malt Vinegar is preferred, while in the United States Cider 
Vinegar is regarded as the standard product. Owing to the 
high price of cider vinegar and the increased demand, large 
quantities of Distilled Vinegar are now made from dilute 
alcohol, the process being carried on in conjunction with the 
manufacture of compressed yeast. While the distilled product 
is quite as strong as cider vinegar, it is lacking in ethers and 
other flavoring constituents and contains only a very small 




VINEGAR 175 

amount of sugar, phosphates, and other solids, glycerol and 
other constituents characteristic of vinegar made from fer- 
mented liquors. 

Sugar Vinegar or Molasses Vinegar and Glucose Vinegar 
are made in considerable quantities. Dilute acetic acid obtained 
by purifying pyroligneous acid from the dry distillation of wood 
is not regarded as suitable for food. 

Analyses of different kinds of vinegar appear in the table on 
p. 176. 

Process of Manufacture. Mycoderma aceti, the bacterium 
which converts the alcohol into acetic acid (Fig. loi), is widely 
distributed and the spores 
are likely to find their way 
into the barrels of cider or 
other liquor stored with 
open bungholes in the 

farmer's cellar. The proc- ^^^ ,^,._vinegar Bacteria, Mycoderma aceti. 

ess is commonly accel- (Fischer.) 

erated by adding the slimy 

growth known as " mother of vinegar" from a barrel containing 

vinegar already made or in process of making. 

Farmer's or barrel-fermented vinegar requires two or three 
years for developing its full acid strength, owing partly to unfa- 
vorable temperatures, but chiefly to insufficient contact with the 
oxygen of the air, acetous fermentation, unlike alcoholic fermen- 
tation, being an oxidation process, as shown by the following 
equations : 

(1) C2H60-fO = C2H40+H20 

Alcohol Aldehyde Water 

(2) C2H40+0 = C2H402. 

Aldehyde Acetic acid 

Quick-process or generator vinegar is made by allowing the 
cider to drip through beech shavings, previously soaked in old 
vinegar, contained in a cask or vat through which passes a 
current of warm air. By carefully regulating the conditions 
the vinegar is formed in a few days. 



176 



FRUIT PRODUCTS, LIQUORS, AND VINEGAR 



Composition of Vinegar. The following table gives the 
average composition of cider, wine, malt, and distilled vinegar: 

Average Composition or Different Kinds of Vinegar 



Kind of Vinegar. 



Number 
Samples 
Ana- 
lyzed. 



Acidity 

as 
Acetic 
Acid. 



Organic 
Acid 
other 
than 

Acetic. 



Total 
Solids. 



Sugars. 



Ash. 



Phos- 
phoric 

Acid 
(P2O6). 



Cider (Lythgoe) 

Wine (Koenig) 

Malt (Hehner) 

Distilled (Paris Munici- 
pal Lab.) 



22 
17 

7 



4.84 

5-57 
4 23 

6.34 



O. II 

0.13 



2.49 
1.89 
2 . 70 

0.35 



0,25 
0-35 



trace 



0-34 
o. 27 

0-34 
0.04 



0035 
0053 
0.105 



' Malic, free and combined. 
- Tartaric, free and combined. 



From the figures in the table it is evident that distilled vin- 
egar is readily distinguished from cider, wine, and malt vinegars 
by the low percentages of total solids and ash. As a safeguard 
against adulteration with distilled vinegar, as well as dilution, 
the Federal standard and the laws in certain states require that 
cider vinegar contain at least 4 grams of acetic acid and 1.6 
grams of solids in 100 cc. But a minimum figure for solids 
alone does not suffice, as boiled sweet cider can readily be added 
in sufficient amount to bring the percentage of solids above 
the limit. To prevent this fraud, the standard requires that 
the sohds contain not more than 50 per cent of reducing sugars, 
and also fixes the minimum percentages of ash, phosphoric 
acid, and alkalinity of ash. 

To illustrate, i part of sweet cider containing over 13 per 
cent of sohds, the average of Browne's results (p. 165) mixed 
with 7 parts of distilled vinegar would contain over 1.60 per cent 
of solids, but the amount of sugar in the solids would greatly 
exceed 50 per cent; furthermore the minimum limits for ash, 
phosphoric acid, and alkahnity of ash would not be reached. 
Frear, who suggested the ratio of sugars to total solids as required 
in the above standard, also pointed out the importance of the 



SOLIDS AND ACIDITY IN VINEGAR 177 

ratio of ash to total solids. Naturally this ratio is much less in 
sweet cider or in distilled vinegar mixed with sweet cidei than 
in cider vinegar. A certain amount of glycerol is also a char- 
acteristic of cider and wine vinegar as well as of the fermented 
liquors from which they are made. The analyses made by Ross, 
by Bender, and by Goodenow have established 0.24 per cent of 
glycerol as the minimum for generator vinegar. 

The distinction of wine and malt vinegars from other kinds 
is not so important in the United States as in Europe. Wine 
vinegar is characterized by the presence of tartaric acid, free 
and combined as cream of tartar (potassium bitartrate) or in 
other combination, whereas the non- volatile acid of cider vine- 
gar is largely malic. Malt vinegar usually contains more solids 
and phosphoric acid than cider or wine vinegar and is also char- 
acterized by the presence of dextrin and maltose. Glucose 
vinegar and molasses or sugar vinegar are relatively of small 
importance. The former is dextro-rotatory both before and 
after inversion, the latter is dextro-rotatory before but levo- 
rotatory after inversion. Cider vinegar is invariably levo- 
rotatory. 

^Determination of Solids and Acidity in Vinegar. See pp. 
166 and 168. The determination of other constituents need not 
be taken up in this short course. They are of interest chiefly 
in food inspection. 

Various Fruit Products 

A great variety of food products formerly prepared only in 
the household are now made and put up in suitable containers 
in large establishments. Among the best known are canned 
fruits, dried fruits, preserves, jellies, catsup, and mince-meat. 

Methods of Analysis. The products named may be anal- 
yzed by the methods described in Chapter IV and on the 
foregoing pages of this chapter, introducing slight modifica- 
tions when needed. 

Preservatives. Only two chemical preservatives are now 
used to any considerable extent in fruit products made in the 



178 FRUIT PRODUCTS, LIQUORS, AND VINEGAR 

United States. These are, (i) Sulphur Dioxide, employed in 
bleaching as well as preserving dried fruits, and (2) Sodium 
Benzoate, added to preserves, jellies, catsup, and mince-meat. 

Sulphur dioxide is determined by the method described for 
meat products containing sulphites (p. 38), sodium benzoate 
by Dunbar's modification of the La Wall and Bradshaw 
method. The latter method depends on the extraction of the 
benzoic acid by chloroform after adding common salt to hold 
back certain interfering substances. The benzoic acid is 
weighed and in addition may be titrated in an alcoholic 
solution. 



CHAPTER IX 
FLAVORING EXTRACTS 

Food, in the restricted sense, includes only such products 
as furnish the body with materials for the production of mus- 
cular energy, heat, or the repair of tissues; in the broader sense it 
includes products used solely for their flavor, such as spices and 
flavoring extracts, or for their flavor and stunulating properties, 
such as tea and coffee. Proteins and fat in a state of purity have 
little or no flavor and the same is true of starch and dextrins of 
the carbohydrate group. Sugars are the exception among the 
nutritive substances in that they have pronounced flavors. The 
flavor of most natural or manufactured foods is due to minor 
constituents produced in the animal or vegetable organism^ or 
else developed by roasting or other method of preparation. 
When the flavor is lacking or needs modifying, spices, extracts, 
or similar materials are used. 

Distinction of Spices from Extracts. Spices are natural 
products used solely for their flavoring constituents. Although 
they consist chiefly of the substances belonging to the six groups 
considered in Chapter IV, their flavoring power, due to minor 
constituents, is so great that they are used in quantities too 
smafl to aid appreciably in nutrition. The valuable ingredients 
are essential oils and other pungent or aromatic bodies. Often 
the flavor is a blend resulting from the presence of two or more 
constituents. Most flavoring extracts are alcohoHc solutions 
(tinctures) of essential oils such as oil of lemon, orange, almond, 
clove, cinnamon," nutmeg, peppermint, or wintergreen. Vanilla 
extract, however, contains vanillin, a crystalline substance, and 
various other aromatic substances derived by direct extraction of 

the dried fruit. 

179 



180 FLAVORING EXTRACTS 

Nature of the Analytical Methods. In the determination of 
the essential oil in lemon and orange extract a centrifugal method, 
employing the Babcock apparatus, and a polariscopic method, 
involving the technique described in the chapter on sugars 
(p. 131), are used. Vanillin and coumarin are determined 
gravimetrically in vanilla extract and substitutes by extraction 
with immiscible solvents and vaniUin is also estimated color- 
imetrically. Citral, one of the flavoring constituents of lemon 
and orange extract, is also determined by a colorimetric method. 
The analysis of extracts accordingly furnishes varied experience 
and the methods are typical of many others devised for the 
analysis of various materials including, not only foods but 
drugs and other technical products. The experience of carrying 
on two processes at the same time is also valuable. 

In this connection it should be reiterated that the purpose 
of this book is not to describe a great number of tedious processes 
regardless of variety or importance, but rather a carefully selected 
number illustrative of types, striving at the same time to give a 
general idea of the subject of food analysis and the composition 
of foods. Too often the student is staggered by page after page 
of dry description and fails to grasp the subject as a whole or 
to appreciate its absorbing interest and practical importance. 

Vanilla Extract and Substitutes 

Vanilla Beans. The term bean is a misnomer, as the product 
is not the seed of a legume, but the fruit of an orchid {Vanilla 
planifolia). The narrow pods when taken from the plant are 
green and about the size and length of a lead pencil, but on 
drying become black and much shriveled (Fig. 102). They con- 
tain great numbers of black seeds so minute that they form a 
powder. The world's supply comes chiefly from Mexico, the 
insular possessions of France off the coast of Africa (Bourbon 
or Reunion, Madagascar, etc.). South America, and Tahiti, 
the market value diminishing in the order named. The better 
sorts sell for several dollars a pound. They contain, according 
to analyses by Win ton and Berry, from 1.50 to 3.50 per cent of 



VANILLA EXTRACT AND SUBSTITUTES 



181 




vanillin, also other aromatic constituents not yet isolated which 
although present in small amount, contribute 
materially to the delicate flavor. 

Vanillin (CgHgOs) is the methyl ether of 
protocatechuic aldehyde. It may be obtained as 
white crystalline needles either by extraction of 
vanilla beans with ether or other solvents, or 
synthetically by the oxidation of the eugenol of 
oil of cloves with alkaline potassium perman- 
ganate. The synthetic product has sold as low 
as 35 cents per ounce, whereas if made from 
vanilla beans it would cost ten to twenty times 
that amount. In other words only from one- 
tenth to one-twentieth of the cost of vanilla 
beans can properly be attributed to their vanillin 
content, the remainder being paid 
for the other flavoring constit- 
uents. 

Tonka Beans (Fig. 103) are the 
seeds of a tree {Dipterix odoratd) 
native to Guiana. As the tree 
belongs to the Leguminosce the 
seeds are appropriately termed 
beans." They resemble almonds 
in size and shape. The chief 
flavoring constituent is coumarin. 
Coumarin (C9HCO2) is the anhydride of 
coumaric acid. Coumarin is also found in sweet 
grass {Anthoxanthum odoratum) much used in 
Indian basket work, sweet clovers of the genus 
Mellilotus, and sweet woodruff (Aspenda odoratd). 
It is prepared synthetically from salicylic alde- 
hyde, sodium acetate, and acetic anhydride. The 
flavor of coumarin, although somewhat similar to 
that of vanillin, is less agreeable. 

Vanilla Extract. Tincture or extract of vanilla contains the 



Tonka 



Fig. 102. — Vanilla 
Bean. 



182 FLAVORING EXTRACTS 

ingredients of the vanilla bean soluble in 60 per cent alcohol and 
added cane sugar. It is, therefore, quite complicated in its 
composition and belongs in a different class from most flavoring 
extracts such as almond, peppermint, wintergreen, cinnamon, 
cassia, cloves, and nutmeg, which are merely alcoholic solutions 
of essential oils. In addition to vanillin, vanilla extract contains 
brown coloring matter and other substances forming a flocculent 
precipitate with normal lead acetate solution, resin, organic acid, 
and certain ash constituents. 

The formula of a former edition of the United States Phar- 
macopoeia for the preparation of vanilla extract is as fol- 
lows : 

" Vanilla, cut into small pieces and bruised, 100 grams. 

" Sugar, in coarse powder, 200 grams. 

" Alcohol and water, each, a sufficient quantity to make 
1000 cc. 

" Mix alcohol in the proportion of 650 cc. of alcohol to 350 cc. 
of water. Macerate the vanilla in 500 cc. of this mixture for 
twelve hours, then drain off the liquid and set it aside. Transfer 
the vanilla to a mortar, beat it with the sugar into a uniform 
powder, then pack it in a percolator, and pour upon it the 
reserved liquid. When this has disappeared from the surface, 
gradually pour on the menstruum, and continue the percola- 
tion, until 1000 cc. of tincture are obtained." 

Vanilla extract prepared according to this formula varies 
according to Winton and Berry between the following limits: 

Vanillin, o.io to 0.35 gram per 100 cc. 

Normal lead number, 0.40 to 0.80. 

Per cent of color in lead filtrate, not more than 10 per cent 
red or 1 2 per cent yellow. 

Ratio of red to yellow in the extract, not less than i : 2.2. 

Color insoluble in amyl alcohol, not more than 40 per 
cent. 

The range in acidity and ash was found by Winton, Albright, 
and Berry to be as follows: 

Total acidity, 30 to 52 cc. N/io alkah per 100 cc. 



PRACTICE MATERIAL 183 

Acidity, other than vanillin, 14 to 42 cc. N/ 10 alkali per 
100 cc. 

Total ash, 0.220 to 0.432 gram per 100 cc. 

Substitutes for Vanilla Extract. Synthetic vanillin, tonka 
beans, and synthetic coumarin are much used in the preparation 
of flavoring solutions designed as substitutes for or imitations of 
vanilla extract. As both vanillin and coumarin are colorless, 
caramel is commonly added to these solutions in sufficient amount 
to impart a deep coffee color to the liquid. 

Such preparations, although often containing percentages 
of vanillin within the limits for vanilla extract, are characterized 
by their low normal lead number, low acidity other than vanil- 
lin, low ash, low ratio of red to yellow color in the extract, high 
percentages of color, both in the lead filtrate and insoluble in 
amyl alcohol. Coumarin, which is absent in vanilla extract, 
is often present. 

■^^Materials for Laboratory Practice. The analysis of a 
genuine vanilla extract and a substitute, consisting of a solution 
of vanillin and coumarin colored with caramel, will give the 
student sufficient experience for an understanding of the most 
important methods and the interpretation of results. The 
vanilla extract can either be prepared in the laboratory accord- 
ing to the U. S. P. formula or may be obtained of a reputable 
manufacturer. The substitute may be prepared by dissolv- 
ing 2 to 4 grams of vanillin, 0.4 to i.o gram of coumarin, and 
200 grams of sugar in a mixture of equal parts of 95 per cent 
alcohol and water, adding sufficient caramel to impart a deep 
coffee color, and making up to i liter with the same menstruum. 
Care should be taken that the amount of caramel added is not 
sufficient to impart a color too deep to be conveniently measured 
by the Lovibond tintometer. 

The composition of the vanilla extract can be learned only 
by analysis, whereas the precentages of vanillin and coumarin 
in the substitute will be known, at least to the instructor, from 
the quantities used. At least 57 cc. of each preparation should 
be available for each student, 50 cc. for the gravimetric analysis, 



184 FLAVORING EXTRACTS 

5 cc. for the volumetric determination of vanillin, and 2 cc. for 
determining the color value. 

Only single determinations need be made on each material 
by the methods described. The results for vanillin by the two 
methods should check each other, thus serving as duplicates, 
and the single gravimetric analysis in the case of the vanilla 
extract will demonstrate the absence of coumarin quite as well 
as duplicates. The estimation of the color value involves such 
simple manipulation as to preclude the probabihty of error. 
The single result for coumarin in the vanilla substitute and the 
single results for normal lead number in both materials ordinarily 
would require checking, if only a single analyst were involved, 
but for our purpose a comparison of the results of the different 
students will suffice. 

It may here be reiterated that agreeing results by the same 
analyst are often not conclusive, as he is liable to make the 
same error in both determinations. In important work it is 
desirable that the duplicates be made by different analysts and 
if possible with different reagents and apparatus, thus elimi- 
nating the personal equation. 

^Determination of Vanillin and Coumarin by the Modified 
Hess and Prescott Method. This process, in its original form 
devised by Hess and Prescott, has been modified by the author, 
collaborating with Silverman, Bailey, Lott, and Berry, in order 
to prevent loss of coumarin, detect the presence of acetanihde 
(formerly much used as an adulterant of vanillin), and permit 
the determination of normal lead number in the same weighed 
portion.^ It depends on the principle that ammonia water, 
acting on the ether solution of vanillin and coumarin, forms with 
the aldehyde vanillin a compound soluble in water, but does 
not affect the coumarin, which remains in solution in the ether. 

Extraction with Immiscible Solvents. This method is par- 
ticularly instructive, as it is a type of numerous methods involv- 
ing the extraction of one or more constituents from an aqueous 

' Jour. Amer. Chem. Soc, 1899, 21, p. 256; U. S. Dept. Agr., Bur. Chem., 
Bui. 152, p. 147 



VANILLIN AND COUMARIN 



185 



liquid with an immiscible solvent such as ether, chloroform, or 
carbon bisulphide. Various forms of apparatus for the con- 
tinuous extraction of one liquid with another have been devised, 
but for ordinary purposes shaking in a separatory funnel, as 
here described, is preferable. Care must be taken to avoid 
too violent shaking with ether, as otherwise an emulsion will be 
formed which is not easily broken up. The ether should always 
be poured out of the neck of the funnel after drawing off the 




Fig. 104. — Squibb Separatory Funnel. 



aqueous liquid through the stopcock, thus obviating contamina- 
tion with the water-soluble constituents such as the sugar of 
the extract or the ammonium chloride formed by the neutrali- 
zation of ammonium hydroxide. 

Fig. 104 shows the pear-shaped or Squibb form of separatory 
funnel, which is well adapted for the analysis of vanilla extract. 
The support has holes with slots for inserting the separatory 
funnels, but may be used also for ordinary funnels. 

Process. Pipette 50 cc. of the extract directly into a tared 
250-cc. beaker with marks made with diamond ink showing vol- 



186 FLAVORING EXTRACTS 

umes of 80 and 50 cc; dilute to 80 cc. with water boiled until 
free from carbon dioxide, and evaporate to 50 cc. in a pan of 
water kept at 70° C. by a Bunsen burner. Dilute again to 80 cc. 
and evaporate to 50 cc. as before. Transfer to a loo-cc. grad- 
uated flask, rinsing the beaker with hot carbon dioxide-free 
water, taking care not to use more than 25 cc; add 25 cc. of 
standard lead acetate solution (80 grams of chemically pure 
crystallized lead acetate dissolved in water and made up to i 
liter), make up to the mark, shake, and place in a bacteriological 
incubator, in a water bath provided with a thermostat, or in other 
suitable apparatus, kept at a temperature of from 37° to 40° C. 

Two laboratory periods of four hours each will be required 
for the work up to this point. During the first of these periods, 
while the dealcoholizing is proceeding, there will be time to 
determine vanillin by the Folin and Denis method (p. 192). 
The color value of the vanilla and vanilla substitute (p. 189) 
can be determined during the second period; the glass dishes 
for the vanillin and the coumarin can also be weighed. 

On the third day, after the flask has been kept at 37° to 40° 
for eighteen to twenty hours, filter through a small dry filter and 
pipette off 50 cc. of the filtrate into a Squibb separatory funnel 
of 125 cc. capacity. 

For the determination of normal lead number, pipette off 
10 cc. of the filtrate into a beaker and precipitate as described 
on p. 191. Use the remainder of the lead filtrate for the deter- 
mination of color value (see p. 190). This can be carried out 
while the vanillin and coumarin are being shaken out with ether. 
If kept until the next day a cloudiness, due to absorption of 
carbon dioxide and precipitation of lead carbonate, is liable to 
appear. 

To the 50 cc. of the filtrate in the separatory funnel add 20 cc. 
of ether and shake cautiously several times. Draw off carefully 
through the stopcock the aqueous liquid, together with any 
ether emulsion, and then pour the clear ether solution from the 
mouth into a beaker. Return the aqueous solution to the 
separatory funnel and shake out as before using, however, 



VANILLIN AND COUMARIN 187 

15 cc. of ether. Repeat this treatment twice. Reject the 
extracted aqueous hquid and rinse the separatory funnel. 

Pour the combined ether solutions into the rinsed separatory 
funnel, add 10 cc. of 2 per cent ammonium hydroxide solution, 
and shake several times. Draw off the ammoniacal solution 
into a beaker, taking care not to allow any of the ether solution 
to pass through with it. Shake out with three more portions of 
the ammonium hydroxide solution exactly as before, except that 
5 cc. are used. 

Transfer the ether solution, containing the coumarin if 
present and from which the vanillin has been removed in the 

ammoniacal solution, to a weighed low- 

form, glass crystallizing dish, 60 mm. Iflljjl^ jlH 

in diameter, with an etched circle on 
which is placed an identification mark 
with a lead pencil (Fig. 105). 

Add to the combined ammoniacal _ _^=^„^„_^ 

solutions with stirring 10 per cent hydro- 
chloric acid until it is slightly acid to test ^^' ^°^' Y)- P^ ^ '^'^"^ 
paper. This should be done without 

delay, as the ammoniacal solution on standing grows slowly 
darker with a loss of vanillin. Cool, transfer to the separatory 
funnel and shake out the vanilUn with four portions of ether, 
as described for the first ether extraction, removing the ether 
solution each time to a weighed crystallizing dish. Allow the 
ether in this crystallizing dish, as well as that in the crystalliz- 
ing dish containing the ethereal solution of the coumarin, to 
evaporate at room temperature until the next day. Do not 
attempt to hasten the evaporation of the ether by heating or 
by an air current, as this will cause condensation of moisture 
in the dishes, owing to the lowering of the temperature. 

On the following day (the fourth of the work on extracts), 
place the crystallizing dishes in a sulphuric acid desiccator, then 
finish the determination of normal lead number as described on 

P- 191- 

On the fifth day weigh the dishes containing the vaniUin 



188 FLAVORING EXTRACTS 

and coumarin and calculate the weight per loo cc. of each. The 
genuine vanilla extract will, of course, contain no coumarin. 
although a very small amount of resinous material may be 
obtained which, were it crystalline and present in considerable 
amount, would be considered coumarin. 

In the vanilla substitute the crystals of coumarin are recog- 
nized by their needle shape and characteristic odor. Deter- 
mine the melting-point as described below and subject the re- 
mainder to the Leach test (p. 189). The identification of the 
coumarin is essential, as its presence constitutes an adulteration 
in a preparation purporting to be pure vanilla extract. At one 
time synthetic vaniUin was often adulterated with acetanilide, 
which, by the process above described, would be' largely weighed 
with the coumarin but could be subsequently separated. 

^Determination of the Melting-point of Coumarin. The 
melting-point, so often determined in the organic laboratory, 
serves for the identification of many crystalline substances. 

The required apparatus is the same as that used for deter- 
mining the melting-point of fats (Fig. 96), except that the flask 
and tube are smaller and the capillary tubes are closed at the 
lower end. Instead of water, concentrated sulphuric acid is used. 

Introduce a crystal or two of the substance into a capillary 
tube closed at one end and place this against the bulb of the 
thermometer where it adheres owing to the viscosity of the acid. 
Slowly heat the acid in the flask over a Bunsen burner. The 
heat is communicated to the acid in the inner tube and finally 
to the substance in the capillary tube. Note the temperature 
at which the crystal melts. 

To make capillary tubes suitable for melting-point deter- 
minations, heat the middle part of a test-tube and draw down 
to the size of the lead in a pencil, cut into lengths of about i| in., 
and close one end of each, by fusing. 

The melting-point of pure coumarin is 67° C. That obtained 
in the analysis may melt slightly below that temperature, as 
any impurity depresses the melting-point. The variation from 
67° should, however, not be more than a degree or two. 



COUMARIN TEST; COLOR VALUES 



189 



Leach Test for Coumarin. To the portion of the crystals 
remaining in the crystaUizing dish (p. i88), add a few drops of 
water, warm gently, and add a few drops of a solution of iodine 
in potassium iodide. In the presence of coumarin a brown 
precipitate will form which, on stirring with the rod, will soon 
gather in dark-green flocks. 

^Determination of Color Value of Vanilla Extract and Sub- 




FiG. 1 06. — Lovibond Tintometer. 

stitutes. The Lovibond Tintometer (shown in Fig. 106), is a 
simple instrument so arranged that light is reflected from a 
square of opal glass R, through a cell with glass sides C, con- 
taining the liquid under examination, and at the same time 
through standard colored glass slides S, added, one by one, to 
a carrier until the colors, as seen through an eyepiece 0, match. 
The standard slides used in general work are red, yellow, and 



190 FLAVORING EXTRACTS 

blue in even graduation from .006 to 20 tint units, which can be 
combined so as to produce any desired tint or shade of any color. 
The results are expressed in terms of standard dominant colors 
(red, yellow, and blue), subordinate colors (orange, green, and 
violet), obtained by combining equal values of two dominant 
colors, and neutral tint (black), obtained by combining equal 
values of the three dominant colors. 

Thus o.6i? + 5.67=o.60+5.oF, 

o.o8i?+i.5F+o.25 = o.o8iV+o.i2G+i.3F, 
i.2R-\-i.oB = i.oVi-o.2R 

in which R=red, F= yellow, 5= blue, 0= orange, G= green, 
V = violet, and N = neutral tint or black. 

For vanilla extract work only the following 17 slides are 
needed : 

Red, 5.0, 2.0, 2.0, i.o, 0.5, 0.2, 0.2, 0.1, 
Yellow, lo.o, 5.0, 2.0, 2.0, 1.0, 0.5, 0.2, 0.2, 0.1. 

It is recommended, however, that a set of blue slides of the 
denominations given for the red be provided for the highly 
instructive study of colors and color combinations. 

Process. Pipette 2 cc. of the extract into a 50-cc. graduated 
flask and make up to the mark with a mixture of equal parts of 
95 per cent alcohol and water. Determine the color value of 
this diluted extract in terms of red and yellow by means of a 
Lovibond tintometer, using the i-in. cell. To obtain the color 
value of the original extract multiply the figures for each color 
by 25. 

For example, a reading of 0.6 red and 2.1 yellow obtained on 
the diluted extract corresponds to a color value of 15 red and 
52 yellow calculated to the original extract. 

^Determination of Residual Color after Precipitation with 
Lead Acetate. As soon as possible after filtration determine 
the color value, in terms of red and yellow, of the filtrate from 
the lead acetate precipitate, obtained in the determination of 



NORMAL LEAD NUMBER 191 

vanillin and coumarin (p. i86), using the i-in. Lovibond cell. 
Multiply the reading by 2, thus reducing the result to the basis 
of the original extract. 

In case the actual reading of the solution is greater than 5 
red and 15 yellow, as may happen if the extract is highly colored 
with caramel, the |- or i-in. ceU should be employed and the 
readings multiplied respectively by 4 or by 8; or else 10 cc. of 
the solution should be diluted to 50 cc. in a graduated flask, 
mixed, examined in the i-in. cell, and the readhig multiplied 

by 10. 

Divide the figures for red and yellow respectively, by the 
corresponding figures of the original extract and multiply the 
quotients by 100, thus obtaining the percentages of the two 
colors remaining in the lead acetate filtrate. 

For example, if the color value of the original extract is 15 
red and 52 yellow and the color value of the lead acetate filtrate, 
also measured in the i-in. cell, is 0.6 red and 2.4 yellow, then the 
residual color, after precipitation with lead acetate, calculated 
to the basis of the original extract, is 1.2 red and 4.8 yellow or 
8 per cent of the red and 9.2 per cent of the yellow. 

^Determination of Normal Lead Number by the Winton and 
Lett Method. Mix the 10 cc aliquot of the filtrate from the 
lead acetate precipitate, obtained in the determination of vanil- 
lin and coumarin (p. 186), with 25 cc. of water, boiled until free 
from carbon dioxide, and a moderate excess of sulphuric acid. 
Add 100 cc. of 95 per cent alcohol and mix again. 

Let stand overnight, collect the lead sulphate on a weighed 
Gooch crucible, wash with six portions of 95 per cent alcohol, 
filling the crucible each time and allowing it to empty before 
adding the next portion, dry at a moderate heat on a piece of 
asbestos paper, ignite at low redness for three minutes, takmg 
care to avoid the reducing flame, cool, and weigh. The normal 
lead number is calculated by the following formula: 

5 



192 FLAVORING EXTRACTS 

in which P = normal lead number, 5 = grams of lead sulphate 
corresponding to 2.5 cc. of the standard lead acetate solution 
as determined in blank analyses, and IF = grams of lead sul- 
phate obtained in 10 cc. of the filtrate from the lead acetate 
precipitate as above described. 

The standard of the lead acetate solution is determined by- 
blank analyses and does not change appreciably on standing in 
a well-stoppered bottle. The beginner probably will not find 
time to determine the standard and can accept the figures 
obtained by the instructor or the more advanced student. 

The normal lead number of the genuine extract should vary 
between the limits given (p. 182), while that of the substitute 
will be practically zero, 

^Determination of Vanillin by the Folin and Denis Method. 
This method^ is based on the fact that vanillin (as well as other 
mono-, di-, and tri-hydric phenol compounds), when treated in 
an acid solution with phosphotungstic-phosphomolybdic acid, 
gives on addition of an excess of sodium carbonate, a beautiful 
deep blue color. It yields accurate results, requires but 5 cc. 
of the material, and is exceedingly rapid. An analyst familiar 
with the process can make ten or twelve determinations in an 
hour, whereas, working under favorable conditions, he would not 
be able to make the same number of determinations by the 
Hess and Prescott method in less than three days. For inspec- 
tion purposes the latter method has the advantage that the 
vanillin and coumarin are obtained in crystalline form for sub- 
sequent tests; furthermore coumarin, normal lead number, and 
color value of the lead filtrate are determined in one weighed 
portion. 

Given the reagents, the student will have no difficulty in 
making determinations of vanillin in the practice samples 
(p. 183), by the Folin and Denis method, while waiting for the 
dealcoholizing required in the Hess and Prescott method. It 
may here be mentioned that it is often necessary for the analyst, 
in order to use his time to the best advantage, not only to carry 

^ Jour. Ind. Eng. Chem., 1912, 4, p. 670. 



CALORIMETRIC ANALYSIS 



193 



along together determinations by the same method on dif- 
ferent samples, but also in the intervals to have in progress 
analyses by entirely different methods. 

Nature oj Colorimetric Methods. The Folin and Denis 
method is typical of nmnerous colorimetric methods in that it 
depends on the formation of a colored compound with the sub- 
stance to be determined, the amount present being estimated 
from the intensity of the coloration of the solution as compared 
with that of a solution containing a known amount of that 
substance treated in the same manner. 
The solution of the unknown may 
either be compared with several solu- 
tions, prepared with different amounts 
of a standard solution, selecting for 
the calculation the one that matches 
in shade, or else it may be compared 
with a single solution, varying the 
height of the column of one or the 
other until the colors reflected through 
the two columns match and calcula- 
ting the result by the rule of three. 
The former procedure is used in de- 
termining the free and albuminoid 
ammonia in potable water by a process 
known as " Nesslerizing," while the 
latter is more commonly employed in 
food analysis. The comparison of the 
solution of the unknown with the 
standard may be made in two tubes, 
each provided with a stopcock at the 
bottom whereby a portion of the 
darker solution may be drawn off until 
the two columns match in tint or else a colorimeter may be used. 

The Schreiner Colorimeter is well adapted for our purpose, 
being inexpensive, of simple construction, and accurate. This 
apparatus, shown in Fig. 107, consists of two graduated tubes 




Fig. 107. — Schreiner 
Colorimeter. 



194 FLAVORING EXTRACTS 

B, containing the standard and unknown colorimetric solutions, 
the height of the column of liquid in both tubes being changed 
by two immersion tubes A, which remain stationary while the 
graduated tubes are raised or lowered in the clamps C. The 
mirror D reflects the Hght through the tubes, and the mirror E 
reflects it again to the eye of the operator at F. 

In making the comparisons the tube containing the solution 
of either known or unknown strength is set at a definite point, 
and the other tube is raised or lowered until the colors match. 
If R is the reading of the standard solution of the strength 5, 
and r the reading of the colorimetric solution of unknown strength 
s, then 

R^ 
r 

If desired, standard slides of colored glass, such as accom- 
pany the Lovibond tintometer, may be used at G for matching 
the solution of unknown strength, the value of these slides 
being determined by comparison with a standard solution. 

Suggestions. The student should not be discouraged if at 
first he has difficulty in securing concordant readings in the 
comparison of the two solutions in the colorimeter. Some expe- 
rience is required before the eye can detect slight differences in 
shade and arrive at the exact point where the two solutions 
match in color intensity. The following hints may prove 
helpful : 

Choose a soft but sufficient Hght, best at a north window or 
reflected from the north sky; never use direct sunlight. Prac- 
tice at first with the same solution in both tubes. Do not use 
too high columns, as it is difficult to match deep colors. Avoid 
straining the eyes; adjust the tubes rapidly until the colors 
match approximately, then look away and when the eyes have 
rested a moment make the final adjustment in about five sec- 
onds. Do not attempt colorimetric work when the light is 
poor, when the eyes are tired, or when you are hurried or other- 
wise mentally disturbed. 



VANILLIN BY COLORIMETRIC METHOD 195 

Reagents, (i) Standard Vanillin Solution. Dissolve o.i 
gram of pure vanillin in water and make up to i Uter. 

(2) Phosphotungstic-phosphomolybdic Acid Reagent. To 
100 grams of pure sodium tungstate and 20 grams of phospho- 
molydic acid (free from nitrates and ammonium salts) add 100 
grams of syrupy phosphoric acid (containing 85 per cent H3PO4) 
and 700 cc. of water. Boil over a free flame for one and one-half 
to two hours, cool, filter, if necessary, and make up with water 
to I liter. An equivalent amount of pure molybdic acid may 
be substituted for the phosphomolybdic acid. 

(3) Sodium Carbonate Solution. Prepare a solution of 
the c.p. salt, saturated at room temperature. 

(4) Lead Solution. Dissolve 50 grams each of basic and 
neutral lead acetate in water and make up to i Uter. 

Process. Pipette 5 cc. of the extract or substitute into a 
graduated loo-cc. flask, add about 75 cc. of cold tap water and 

4 cc. of lead solution, make up to the mark with water and shake. 
Filter rapidly through a folded filter paper and pipette 5 cc. of 
the filtrate, corresponding to 0.25 cc. of the extract, into a 50-cc. 
graduated flask. Into another 50-cc. graduated flask pipette 

5 cc. of the standard vanillin solution, which volume contains 
0.0005 gram of vanillin. To each flask add from a pipette 5 cc. 
of the phosphotungstic-phosphomolybdic reagent, directing the 
stream against the neck in such a manner as to wash down 
any adhering vanilUn. Shake the flasks by a rotary motion, 
allow to stand for five minutes, then fill to the mark with sat- 
urated sodium carbonate solution. Thoroughly mix the con- 
tents of the flasks by inverting several times and allow to stand 
for ten minutes in order that the precipitation of sodium phos- 
phate may be complete. Filter rapidly through folded filters 
and compare the color of the deep-blue solutions, which must be 
clear, in the colorimeter. 

In this, as in all colorimetric methods, a slight cloudiness of 
the solution of the unknown, by cutting off more light than 
the standard, gives a low reading and correspondingly high 
result. 



196 FLAVORING EXTRACTS 

Calculate the grams of vanillin per loo cc. as follows: 

P = ^ = — 

o.2sr 5r 

in which P is the grams of vanillin per loo cc, R is the reading 
of the standard solution and r is the reading of the unknown 
solution in the colorimeter. 

Determination of Other Constituents. Sucrose is calculated 
from the polariscopic readings (p. 133), and Alcohol from the 
specific gravity of the distillate obtained by direct distillation 
as in the case of a liquor (p, 172). The amount of neither of 
these constituents throws any light on the genuineness of an 
extract; on the other hand, the percentage of Ash and the Acidity 
other than vanillin, as shown by Winton, Albright, and Berry, 
bear a striking relation to the normal lead number and are 
valuable in distinguishing genuine vanilla extract from solutions 
of vanillin and coumarin. The solubility and alkalinity of the 
ash serve to detect the presence of added alkali in vanilla 
extract. 

The total acidity is determined by titration, using phenol- 
phthalein as an indicator, the acidity due to vanillin by calcu- 
lation from the percentage of that constituent. Total ash is 
determined by evaporation and incineration at a dull red heat. 

Lemon Extract 

Lemon Oil is the essential oil obtained from lemon peel. 
The chief regions of production are Sicily and adjoining parts 
of the ItaHan mainland, where the manufacture of oil from the 
peel and citrate of hme from the pulp are carried on in the same 
factories. Commercial citric acid is obtained by heating citrate 
of lime with sulphuric acid. 

Limonene (CioHie), a dextro-rotatory terpene with a strong 
flavor, makes up about 90 per cent of lemon oil; Citral (CioHieO), 
an aldehyde with a delicate flavor and the characteristic odor 
of lemon peel is present to the extent of 4 to 5 per cent. Both 



LEMON EXTRACT 197 

of these substances occur in the peel of other citrus fruits, and 
citral is also present in lemon grass. Commercial citral is 
obtained from lemon grass or artificially by the oxidation of 
geraniol. Limonene is soluble in strong alcohol, but insoluble 
in dilute alcohol, while citral is soluble in both. 

Lemon Extract as recognized by Federal and State standards, 
as well as by the trade, is a solution in strong alcohol of at least 
5 per cent by volume of lemon oil, with or without the coloring 
matter and other extractive substances of lemon peel. When 
diluted with water, it becomes cloudy, due to the precipitation 
of the limonene. The flavor, aside from that of the alcohol, 
which evaporates in cooking or is lost by dilution, is a combina- 
tion of the strong taste of limonene and the delicate aroma 
of citral. 

Terpeneless Lemon Extract is a solution prepared by shaking 
lemon oil with dilute alcohol or dissolving so-called terpeneless 
lemon oil in that solvent and should contain at least 0.2 per cent, 
by weight, of citral. It is used for flavoring soda water and other 
liquids to which lemon extract would impart a turbidity. As 
under ordinary market conditions the cost of a lemon extract is 
due more to the alcohol than to the lemon oil, the cheaper ter- 
peneless extract is often sold for family use and has not always 
been labeled so as to show its true character. 

^Material for Laboratory Practice. A lemon extract con- 
taining from 5 to 8 per cent of lemon oil dissolved in 95 per cent 
alcohol and a terpeneless extract containing 0.20 to 0.30 per cent 
of citral, prepared by dissolving i gram of terpeneless lemon oil 
in 300 cc. of 50 per cent alcohol, are suited for analytical practice. 
These may either be prepared in the laboratory or obtained 
from the manufacturer or grocer. 

Dilute a portion of the terpeneless extract with an equal 
volume of water. No cloudiness should appear, showing that 
lemon oil is not present and that a quantitative determination 
of this substance is unnecessary. 

Arrangement of Time. On the day when the vanillin and 
coumarin, obtained in the analysis of vanilla extract and sub- 



198 FLAVORING EXTRACTS 

stitute, are weighed (p. 187), time will be found to determine 
lemon oil by Mitchell's two methods ^ in the lemon extract. 
As the polarization method involves no manipulation other 
than direct polarization and the centrifugal method serves as a 
check, a single determination by each method will suffice. 

Citral can be determined in both samples on the following 
day, after the extraction of caffeine from coffee has been started 
(p. 205). 

^Determination of Lemon Oil by the Mitchell Polariscopic 
Method. Polarize the extract, without dilution, in a 200-mm. 
tube in the same manner as is described in Chapter VI. Divide 
the reading obtained in degrees Ventzke on the sugar scale by 
the factor 3.2. If sugar or other optically active substances are 
not present, as is almost always the case, the quotient will be 
the per cent of lemon oil by volume. 

^Determination of Lemon Oil by the Mitchell Centrifugal 
Method. Pipette 20 cc. of the extract into a Babcock milk- 
test bottle (p. 19), add i cc. of dilute hydrochloric acid (1:1) 
and 25 to 28 cc. of water previously warmed to 60° C, mix, and 
let stand in water at 60° C. for five minutes, whirl in a centrif- 
ugal machine five minutes, as in milk analysis, fiU with water 
at 60° nearly to the 10 per cent graduation, and whirl again for 
two minutes. Immerse in water at 60° nearly to the top of the 
neck for a few minutes and finaUy read the length of the column 
exactly as in the Babcock test. When the result is over 2 per 
cent add 0.4 per cent to correct for lemon oil retained in the 
solution, when less than 2 per cent but more than i per cent, 
add 0.3 per cent. The result thus corrected should agree with 
that by the polarization method within 0.2 per cent. 

A marked disagreement by the two methods would indicate 
the presence of a foreign essential oil, such as oil of citronella, 
in which case the oil layer obtained in the test bottle should be 
examined as to its refractive index and other properties. For- 
tunately such addition is rarely, if ever, practiced. 

^Determination of Citral by the Hiltner Method. This 

'Jour. Amer. Chem. Soc, 1899, 21, p. 1132. 



CITRAL IN LEMON EXTRACT 199 

colorimetric method ^ measures the strength of terpeneless lemon 
extracts and also detects the substitution in lemon extract of 
" washed lemon oil," the residual oil after shaking with dilute 
alcohol in the manufacture of terpeneless extracts, for natural 
lemon oil. A lemon extract made from washed lemon oil will 
naturally be deficient in citral. 

Reagents, (i) Metaphenylene Diamine Hydrochloride 
Solution. Prepare a i per cent solution in 50 per cent ethyl 
alcohol. Decolorize by shaking with fuller's earth or animal 
charcoal, and filter through a double filter. The solution should 
be bright and clear, free from suspended matter, and practically 
colorless. It is well to prepare only enough for the day's work, as 
it darkens on standing. The color may be removed from old 
solutions by shaking again with fuller's earth. This reagent 
gives a yellow color with citral but no appreciable color with the 
other aldehydes present in lemon extract or lemon oils. 

(2) Standard Citral Solution. Dissolve 0.25 gram of c.p. 
citral in 50 per cent ethyl alcohol and make up the solution to 
250 cc. 

(3) Alcohol. For the analysis of lemon extracts 90 to 95 
per cent alcohol should be used, but for terpeneless extracts 
40 to 50 per cent strength is sufficient. Filter to remove any 
suspended matter. If not practically colorless, render sHghtly 
alkahne with sodium hydroxide and distill. Purification from 
aldehyde is unnecessary. 

Process. All the operations are carried out at room temper- 
ature. Weigh into a 50-cc. graduated flask 25 grams of the 
extract, make up to the mark with alcohol, and mix thoroughly. 
This diluted extract can be used by the whole class. Pipette 
into a 50-cc. graduated flask 2 cc. of the diluted extract (equiva- 
lent to I gram of the original extact), add 10 cc. of metaphenylene 
diamine hydrochloride solution, make up to the mark with alco- 
hol, and shake. Into another 50-cc. flask pipette 2 cc. of the 
standard citral solution (containing 0.002 gram of citral), add 
10 cc. of metaphenylene diamine hydrochloride solution, make 

1 Jour. Ind. Eng. Chem., 1909, i, p. 798. 



200 FLAVORING EXTRACTS 

up to the mark with alcohol, and shake. Compare at once the 
color of the two solutions in the Schreiner colorimeter (p. 193). 
Calculate the result by the following formula: 

jj_0.002RXlOO _o.2R 

J-- _ ^ 

r r 

in which P is the per cent by weight of citral, R is the reading 
of the standard solution, and r is the reading of the unknown 
solution in the colorimeter. 

Determination of Other Constituents. Alcohol is deter- 
mined in a portion of the extract from which lemon oil has been 
removed by dilution, shaking with magnesium carbonate, and 
filtration. The oil which is precipitated by dilution is mechan- 
ically held by the magnesium carbonate, thus affording a clear 
filtrate. The alcohol is obtained from an aliquot of the filtrate 
by distillation and its amount calculated from the specific 
gravity. 

Total Aldehydes are estimated by a method devised by 
Chace, depending on the amount of color developed in a solution 
of the dye fuchsin, which has been decolorized by sulphur 
dioxide. Practically all the aldehyde content of lemon extract 
or terpeneless lemon extract is citral. Other aldehydes are 
present in orange extract. Neither the alcohol nor the total 
aldehydes need be determined by the student. 

Coloring Matter if of coal-tar origin is detected by the usual 
methods, if from lemon peel by Albrech's method. 

Analysis of Other Extracts. Orange Extract is analyzed by 
practically the same methods as lemon extract. 

Denis and Dunbar ^ have devised a method for the deter- 
mination of benzaldehyde, the chief constituent of Almond 
Extract, based on its precipitation as hydrozone with phenyl 
hydrazine. Hortvet and West - oxidize it to benzoic acid. 

Wintergreen oil is determined in Wintergreen Extract by the 
Hortvet and West method ^ depending on its conversion first 

^ Jour. Ind. Eng. Chem., 1909, i, p. 256. 
2 Ibid., p. 84. 



VARIOUS EXTRACTS 201 

into potassium salicylate by boiling with potassium hydroxide 
and hydrogen peroxide solution and finally into salicylic acid 
by treatment with hydrochloric acid. 

Peppermint oil is determined in Peppermint Extract by C. D. 
Howard's modification ^ of Mitchell's centrifugal method. 

The essential oils in various Spice Extracts are estimated by 
methods devised by Hortvet and West ^ and CD. Howard.^ 

'Jour. Amer. Chem. Soc, 1908, 30, p. 608. 
-Jour. Ind. Eng. Chem., 1909, i, p. 84. 



CHAPTER X 
COFFEE, TEA, AND COCOA 

Food Value of Alkaloidal Beverages. Coffee and tea are 
valuable solely because of their flavoring and stimulating prop- 
erties. A cup of either beverage has practically no food value 
except what is due to added milk, cream, and sugar. The quan- 
tity of the material used per cup is itself small and of this only a 
portion goes into solution in the water with which it is boiled 
or steeped; the remainder contained in the coffee grounds or 
spent tea leaves is rejected. 

Chocolate, as such, and after removal of a portion of the 
fat, in which form it is known as cocoa, on the other hand, is not 
merely a flavor and stimulant, but a concentrated food, rich 
in fat and protein and valuable also for its starch. 

The Stimulating Principles of alkaloidal beverages, Caf- 
feine and Theobromine, the former being present in all these, 
the latter only in cocoa and chocolate, have been shown by 
Emil Fischer to be purin derivatives, closely related to xan- 
thine. Their structural formulae, which follow, show them to 
be respectively tri- and di-methyl xanthine. 

NCCHs)— CO NH CO 

II II 

CO C— N(CH3)s. CO C— N(CH3)\ 

I II >CH I II ^CH 

NCCHs)— C W N(CH3)— C W 

Caffeine Theobromine 

NH— CO 

I I 

CO C— NH\ 

I II >CH 

NH— C W 

Xanthine 

203 



204 



COFFEE, TEA, AND COCOA 



These bases are also grouped with the alkaloids. Formerly the 
principle of tea was known as theine, but more recently it has 
been shown to be identical with the caffeine of coffee. Caffeine 
is present in chocolate and cocoa in smaller amounts than theo- 
bromine. 

It is a remarkable fact that these stimulants are associated 
with flavors which are particularly acceptable to the human 
race and that of the tens of thousands of other plants not con- 
taining a stimulant none yields an infusion that attracts the 
appetite like these three " cups that cheer." 

Flavors by a strange psychological association lead man not 
only to the true elements of nutrition he needs, but also to the 
stimulants he craves. 

The Microscopic Structure of the three products (pp. ii8 to 
122) should be kept constantly in mind in considering the 
analyses given in this chapter. The study of structure and 
chemical composition of natural vegetable products should 
always go hand in hand, one throwing light on the other. 

Coffee 

Composition of Coffee. The following table is based on 
analyses by Lythgoe ^ obtained on roasted samples of Santos, 
Porto Rico, Rio, Mocha, and Java coffees: 



Moisture 

Fat (petroleum ether extract 

Crude fiber 

Protein 

Caffeine 

Ash 

Nitrogen-free extract 



Hot water extract ^ . 



Average. 



2 . 16 

13-75 
13 03 
12 .00 
1 . 20 
403 
53 83 



100.00 

25.80 



Maximum. 


3-44 


15 


18 


14 


75 


13 


75 


I 


34 


4 


38 


55 


72 


27 


70 



Minimum. 

1.26 
12.28 
II .02 
10.50 

I . 10 

3-74 
49.29 

24.60 



^ Technology Quarterly, 1905, 18, p. 236. Other constituents were also deter- 
mined. 

2 Calculated from the 10 per cent extract obtained by boiling one hour accord- 
ing to McGill's method. 



CAFFEINE IN COFFEE 205 

From the above figures it will be seen that only about one- 
quarter of the coffee was extracted by boiling with water, the 
remainder being of no value to the consumer. 

In addition to the constituents given in the table coffee 
contains a tannic acid known as caffetannic acid. C. D. Howard 
found 1 1. 1 7 per cent of this acid in a sample of Java and Mocha 
coffee and Shanley 9.47 to 9.96 per cent in samples of Java, 
Mocha, and Rio coffee. 

Coffee Substitutes. Chicory, the root of a plant related to 
the dandelion, is frequently mixed with coffee, imparting a 
sweetish taste and a deep-brown coloration. It yields more 
extractive matter when boiled with water than coffee. 

Other Substitutes are made by roasting Barley, Malt, Wheat, 
Rye, Peas, Figs, Dried Bananas, Dried Beet Root, and various 
other products. 

Most of the substitutes sink when stirred with cold water, 
whereas coffee floats. Microscopic examination will usually dis- 
close the nature of the material provided it has not been roasted 
beyond recognition. Cereal products, peas, and bananas are 
rich in starch; chicory, figs, bananas, and beet root are rich in 
sugar. Neither starch nor an appreciable amount of sugar is 
present in coffee. 

^Determination of Caffeine in Coffee by the Goiter Method. 
Material for Laboratory Practice. Powder a sample of coffee 
so it will pass a 25-mesh sieve. On this material determine 
caffeine in duplicate. The work requires three laboratory 
periods of four hours each, but during the first period, after the 
extraction has been started, there will be sufficient time to 
determine citral in the samples of lemon and terpeneless lemon 
extract (p. 198). 

No other analytical work need be done on coffee, tea, or 
cocoa, as most of the methods are those already used in the 
analysis of other products or are such as can be understood 
from a brief description. 

Process} Mix 11 grams of the powdered coffee with 3 cc. 

* Liebig's .\nnalen, 1908, 358, p. 327. 



206 COFFEE, TEA, AND COCOA 

of water, allow to stand for thirty minutes, and place in the inner 
tube of a Johnson extractor. Should the tube be too small to 
hold the moistened coffee, use proportionately less of both the 
coffee and water. Connect an extraction flask (not weighed) 
and pour through the coft"ee sufficient chloroform to penetrate 
the mass and half fill the flask. Extract, as described on p. 56, 
for three hours. At the end of the extraction or on the next 
day, evaporate off the chloroform from the flask, taking care to 
avoid too \iolent ebullition with consequent mechanical loss. 

Treat the residue in the flask with 5- to lo-cc. portions of 
boiling water, filtering each time through a plug of cotton con- 
tained in the stem of a fmmel into a 55-cc. graduated flask. 
Cool to room temperature, make up to the mark, mix by invert- 
ing several times and pipette off 50 cc. (equivalent to 10 grams 
of the coffee) into a 125-cc. separatory funnel. 

Shake with four portions of 15 cc. each of chloroform, as 
described for vanilla extract (p. 1S6). As the chloroform, unlike 
ether, forms a layer below the aqueous liquid, it may be drawn 
off each time through the stopcock. Use for collecting the four 
portions of chloroform a weighed tinned lead, aluminum, por- 
celain, or glass dish, which can be kept at a gentle heat so that 
while shaking with one portion, the preceding portion can be 
evaporating. Finish the evaporation and dry in a boiling 
water oven for one hour, cool in a desiccator, and weigh. Repeat 
the heating for one hour and weigh again. If the weight is 
constant, calculate the percentage of dry residue, which should 
be practically pure caffeme. In very exact work the nitrogen 
in the residue should be determined and the caffeine calculated, 
using the factor 3.464, but for our purpose the result obtained 
from the weight of the residue is sufficiently accurate, pro\'ided 
due care has been taken in the manipulation. 

Other Methods for the Analysis of Coffee. The methods 
for the determination of Water, Fat, Crude Fiber, Total Xitrogen, 
and Ash are those described in Chapter IV. The per cent of 
Nitrogen as Calcine is obtained by multiplying the per cent of 
caffeine by the factor 0.2SS6. To obtain the per cent of Pro- 



TEA 



207 



tein subtract the caffeine nitrogen from the total nitrogen and 
multiply by 6.25. 

Cafetannic Acid is extracted by 90 per cent alcohol, precip- 
itated with lead acetate, and weighed, after drying at icx)° C. 
as lead caffetannate, by Krug's method.^ 

Tea 

Composition of Tea. Koenig - has compiled the results of 
158 analyses of tea by different chemists with the following 
results: 



Average. 



Maximum. 



Moisture 

Nonvolatile ether extract. 

Essential oil 

Crude fiber 

Protein 

Theine (caffeine) 

Ash 



Tannin 

Nitrogen-free extract other than 
tannin 



8.46 

8.24 

0.68 

10.61 

24- 13 
2.79 

5-93 
12.35 

26.81 



Minimum. 



II 


97 


15 


15 


15 


50 


38 


65 


4 


67 


8 


03 


25 


20 



3 


93 


3 


61 


8 


51 


18 


19 


I 


09 


4 


10 


4 


48 



Kenrick ^ in the analysis of 53 samples of Chinese, Japanese, 
and Indian teas found that from 23.37 to 38.53 per cent of soHds 
were extracted by a ten-minute infusion. 

Coloring and Facing. Formerly green tea was colored by 
a blue pigment such as Prussian blue, ultramarine, or indigo, 
often with the addition of turmeric or some other yellow color, 
but the practice has now been largely discontinued. The pig- 
ments are readily seen in the siftings examined under a lens and 
their identity is established by simple micro-chemical tests. 

1 U. S. Dept. Agr., Div. Chem., Bui. 13, p. 908. 

* Chemie der RIenschlichen Nahrungs- und Genussmittel. 

' Canada Inland Revenue Dept., Bui. 24. 



208 COFFEE, TEA, AND COCOA 

Facing of green tea with talc or clay and of black tea with 
plumbago and other black powders is also now seldom prac- 
ticed. 

Foreign Leaves and Spent Tea Leaves at one time were 
added to tea in the country of production. If a small handful 
of tea is brought to boiling with water and the leaves thus soft- 
ened are spread out on paper, the form, size, and dentation of 
the leaves can be noted (Fig. 79). At the present time such an 
examination will seldom, if ever, disclose foreign leaves, but it 
will serve to bring out the size and maturity of the leaves, and 
the presence of stems and similar impurities. 

The percentage of hot-water extract, as determined by a 
conventional method, was used to detect spent leaves. 

Analysis of Tea, The methods described in Chapter IV 
are applicable to tea. 

Caffeme is determined by direct weighing, as in the case of 
coflfee, but the details of the process are different due to the pres- 
ence of tannin and other interfering substances. One of the 
best processes is that of Stahlschmidt, as modified by AUen,i 
in which the tannin is precipitated from a water infusion by lead 
acetate and the excess of lead in the filtered solution is removed 
by precipitation with sodium phosphate previous to extraction 
of the caffeine. 

Tannin is estimated by oxidation with a standard solution of 
potassium permanganate, using indigo carmine as an indicator, 
as first proposed by Lowenthal and afterwards modified by 
Proctor.- Since other oxidizable substances are present it is 
necessary to make two titrations, one of the infusion directly to 
obtain the total oxidizable substances and another, after removal 
of the tannin by precipitation with gelatin. The difference be- 
tween the two titrations represents the tannin. 

' Commercial Organic Analysis, 4th ed., Vol. VI, p. 607. 
^ Jour. Soc. Chem. Ind., 3, p. 82. 



CHOCOLATE AND COCOA 



209 



Chocolate and Cocoa 

Composition of Cocoa Products. A summary of analyses of 
17 varieties of unground Chocolate {Cocoa Nibs), made by 
Winton, Silverman, and Bailey ^ appears in the following table: 

Composition of Chocolate 





Average. 


Maximum. 


Minimum. 


Water 

Fat 

Crude fiber 


2.72 
50.12 
2.64 
1.04 
0.40 
12. 12 
3-32 
8.07 

1957 


3.18 

52.25 

3.20 

1.32 

0.73 
13.06 

4-15 
8.99 

21 .07 


2. 29 

48.11 

2. 21 


Theobromine 

Caffeine 

Protein 


0.82 

0. 14 

II .00 


Ash 

Starch 

Nitrogen-free extract other than 
starch 


2.61 
6.49 

17.69 




100.00 





The composition of Cocoa is the same as that of the chocolate 
from which it was made allowing for the fat removed and, in 
the case of so-called Dutch cocoa, for the alkali added to aid in 
forming a more complete emulsion in the preparation of the 
beverage. 

Compounds of chocolate and cocoa with starch or flour are 
now unusual. Formerly they were sold fraudulently. 

Cocoa Shells are used for preparing a mild beverage. When 
ground to an impalpable powder they are said to be added to 
cocoa. 

Sweet Chocolate and Sweet Cocoa are mixtures containing 
sugar and often vanilla, vanillin, spices, or other flavors. 

Milk Chocolate contains milk powder and usually also sugar 
and flavoring. 

' Conn. Agrl. Expt. Sta. Rept., 1902, p. 282. 



210 COFFEE, TEA, AND COCOA 

Analysis of Chocolate and Cocoa. All the methods employed 
in the analysis of cereals and other natural vegetable foods, as 
described in Chapter IV, may be used for cocoa products. It 
should be noted, however, that the filtrations in the determina- 
tion of fat and fiber are very slow and the method for starch 
requires preliminary extraction of the fat by ether or gasohne 
and of sugars (if present) by water. 

Theobromine and Caffeine are determined by the Decker 
method.^ The material, together with calcined magnesia, is 
boiled with water and the liquid filtered. The filtrate is evap- 
orated to dryness and the residue extracted with chloroform. 
On evaporation of the chloroform a nearly pure mixture of the 
two alkaloids is obtained, which is weighed. 

Caffeine is removed from the mixture by benzol, in which 
theobromine is insoluble at room temperature. 

If a direct determination is desired the theobromine in the 
residue is treated according to Kunze's ^ method, based on the 
formation of silver theobromine when silver nitrate is added to 
an ammoniacal solution of the alkaloid. 

' Schweiz, Wchshr. Pharm., 1902, 40, pp. 527, 541, 553. 
"Ztschr. anal. Chemie, 1894, 33, p. i. 



APPENDIX 



CALCULATION TABLES 

VIETH'S TABLE FOR CORRECTING QUEVENNE LACTOMETER READ- 
INGS FOR TEMPERATURE 



E 


egrees Degrees of Thermometer (Fahrenheit). 

of 


L 


actom- 


































eter. 45 


46 


47 


48 


49 


so 


51 


S2 


S3 


S4 


55 


S6 


57 


58 


S9 


60 


20 


»9-c 


19.0 


19. 1 


19. 1 


19.2 


19.2 


19-3 


19.4 


19.4 


19-5 


19.6 


19.7 


19.8 


19.9 


19.9 


— 


21 


...... 19-9 


20.0 


20.0 


20.1 


20.2 


20.2 


20.3 


20.3 


20.4 


20.5 


20.6 


20.7 


20.8 


20.9 


20.9 


— 


32 


...... 20. g 


21. a 


21.0 


21. 1 


21.2 


21.2 


21.3 


21-3 


21,4 


21-5 


21.6 


21.7 


21.8 


21.9 


21.9 


— 


23 


21. 9 


22.0 


22.0 


22.1 


22.2 


22.2 


22.3 


22.3 


22.4 


22.5 


22.6 


22.7 


22.8 


22.8 


22.9 


' — 


24 


22-9 


22.9 


23.0 


23.1 


23.2 


23-2 


23-3 


23-3 


23-4 


23-5 


23.6 


23.6 


23-7 


23.8 


23-9 


— 


35 


23.8 


23-9 


24.0 


24.0 


24.1 


24.1 


24.2 


24-3 


24.4 


24-5 


24.6 


24.6 


24-7 


24.8 


24-9 


— 


26 


- 24^8 


24.9 


24.9 


25.0 


25-1 


25-1 


25-2 


25-2 


25-3 


25-4 


25-5 


25.6 


25-7 


25-8 


25-9 


— 


27 


25-« 


25-9 


25-9 


26.0 


26.1 


26.1 


26.2 


26.2 


26.3 


26.4 


26.S 


26.6 


26.7 


26.8 


26.9 


— 


28 


26.7 


26.8 


26.8 


26.9 


27-0 


27.0 


27.1 


27.2 


27-3 


27-4 


27-5 


27.6 


27-7 


27.8 


2.7.9 


— 


29 


27.7 


27.8 


27.8 


27.9 


28.0 


28.0 


28.1 


28.2 


28.3 


28.4 


28.5 


28.6 


28.7 


28.8 


28.9 


— 


30 


28. f 


28.7 


28.7 


28.8 


28.9 


29.0 


29.1 


29.1 


29.2 


29.3 


29-4 


29.6 


29-7 


29.8 


29-9 


— 


31 


29-5 


29.6 


29.6 


29-7 


29.8 


29-9 


30.0 


30.1 


30.2 


30-3 


30-4 


30-S 


30.6 


30.8 


30-9 


— 


32 


30-4 


30.5 


30-5 


30.6 


30-7 


30-9 


31.0 


3I-I 


31-2 


31-3 


31-4 


31-5 


31.6 


31-7 


31-9 


— 


33 


31-2 


31-4 


31-4 


31-5 


31.6 


31.8 


31-9 


32-0 


32-1 


32.3 


32.4 


32. S 


32.6 


32^7 


32-9 


— 


34 


32.2 


32-3 


32-3 


34-4 


32-5 


32-7 


32.9 


33-0 


33-1 


33-2 


33-3 


33-5 


33-6 


33-7 


33-9 


— 


35 


iS-"^ 


33-1 


33-2 


33-4 


33-5 


33-6 


33-8 


33-9 


34-0 


34-2 


34-3 


34-5 


34-6 


34-7 


34-9 


~ 




61 


62 


63 


64 


6s 


66 


67 


68 


69 


70 


71 


7» 


73 


74 


75 


20 




20.1 


20.2 


20.2 


20.3 


20.4 


20.5 


20.6 


20.7 


20.9 


21.0 


21. 1 


21.2 


21.3 


21-5 


21.6 


21 




21. 1 


21.2 


21-3 


21.4 


21-5 


21.6 


21.7 


21.8 


22.0 


22.1 


22.2 


22.3 


22.4 


22.5 


22.6 


22 




22.1 


22.2 


22,3 


22.4 


22.5 


22.6 


22.7 


22.8 


23.0 


23-1 


23-2 


23.3 


23-4 


23-5 


23-7 


23 




23-1 


23.2 


23-3 


23-4 


23-5 


23.6 


23-7 


23-8 


24.0 


24.1 


24.2 


24-3 


24.4 


24.6 


24.7 


24 




24.1 


24.2 


24-3 


24-4 


24-5 


24.6 


24-7 


24-9 


25.0 


25-1 


25.2 


25-3 


25 -5 


25.6 


25-7 


*5 




25-1 


25.2 


25-3 


25-4 


25-5 


25-6 


25-7 


25-9 


26.0 


26.1 


26.2 


26.4 


26.5 


26.6 


26.8 


26 




26.1 


26.2 


26.3 


26.5 


26.6 


26.7 


26.8 


27.0 


27.1 


27.2 


27-3 


27-4 


27-5 


27-7 


27. S 


*7 




27.1 


27-3 


27-4 


27-5 


27.6 


27-7 


27.8 


28.0 


28.1 


28.2 


28.3 


28.4 


28.6 


28.7 


28.9 


28 




28.1 


28.3 


28.4 


28.5 


28.6 


28.7 


28.8 


29.0 


29.1 


29.2 


29.4 


29-5 


29.7 


29.8 


29-9 


29 




29.1 


29-3 


29.4 


29-5 


29.6 


29:8 


29.9 


30-1 


30.2 


3°-3 


30-4 


30-S 


30-7 


30-9 


31-0 


30 




30-1 


30-3 


30-4 


30-S 


30-7 


30.8 


30-9 


31-1 


31-2 


31-3 


31-5 


31.6 


31.8 


31-9 


32-1 


31 




31-2 


31-3 


31-4 


31-5 


31-7 


31-7 


31.8 


32.0 


32-2 


32.4 


32-5 


32.6 


32.8 


33-° 


33-^ 


32 




32-2 


32-3 


32.-5 


32-6 


32-7 


32.9 


33-° 


33-2 


33-3 


33-4 


33-6 


33-7 


33-9 


34-0 


34-2 


33 




33-2 


33-3 


33-5 


33-6 


33-8 


33-9 


34-0 


34-2 


34-3 


34-5 


34.6 


34-7 


34.9 


35-1 


35-2 


34 




34.2 


34-3 


34-5 


34-6 


34-8 


34-9 


3S-0 


35-2 


35-3 


35-5 


35.6 


35-8 


36 


36.1 


36.3 


35 




35-2 


35-3 


35-5 


35-6 


35.8 


35-9 


36-1 


36.2 


36.4 


36.S 


36.7 


36.8 


37.0 


37-2 


37.3 



211 



212 



APPENDIX 



LEACH'S TABLE FOR CALCULATING TOTAL SOLIDS IN MILK BY 
BABCOCK'S FORMULA FROM QUEVENNE LACTOMETER READ- 
ING AND FAT. 



Per 

Cent 
of Fat. 


Lactoqjeter Reading at 15.3° C. 


32 


23 


24 


35 


26 


27 


28 


29 


30 


3t 


32 


33 


34 


35 


36 


o.o 


5.50 


5-75 


6.00 


6:2s 


6. SO 


6.75 


7.00 


7-25 


7.50 


7-75 


8.00 


8.25 


8-So 


8.75 


9.00 


O. I 


S.62 


5.87 


6.12 


6.37 


6.62 


6.87 


7.12 


7-37 


7.62 


7-87 


8.12 


8.37 


8.62 


8.87 


9.1 r 


o.a 


5-74 


5-90 


6.24 


6.49 


6.74 


6.99 


7-24 


7-49 


7-74 


7-90 


8.24 


8.40 


8.74 


8.99 


9.24 


0.3 


5.86 


6. II 


6.36 


6.61 


6.86 


7. II 


7-36 


7.61 


7.86 


8.11 


8.36 


8.61 


8.86 


9. II 


9.36 


0.4 


SQ8 


6.23 


6.48 


6.7.^ 


6.98 


7.23 


7.48 


7.73 


7-98 


8.23 


8. 48 


8.73 


8.90 


9.23 


9.48 


o.s 


6.10 


6.35 


6.60 


6.8s 


7.10 


7.35 


7.60 


7.8s 


8.10 


8.35 


8.60 


8.85 


9.10 


9-35 


9.60 


0.6 


6.32 


6.47 


6.72 


6.97 


7.22 


7.47 


7.72 


7-97 


8.22 


8.47 


8.72 


8.97 


9.22 


9-47 


9.72 


0.7 


6.34 


6.59 


6.84 


7.09 


7.34 


7*-S0 


7-84 


8.00 


8.34 


8.50 


8.84 


9.00 


9-34 


9-59 


9.84 


0.8 


6.46 


6.71 


6.96 


7.21 


7.46 


7.71 


7-96 


8.21 


8.46 


8.71 


8.96 


9.21 


9.46 


9.71 


9.96 


0,9 


6.58 


6.83 


r.o8 


7.33 


7.58 


7.83 


8.08 


8-33 


8.58 


8.83 


9.08 


'9-33 


9-58 


9.83 


10.08 


I.O 


6.70 


6.05 


7.20 


7-45 


7.70 


7.95 


8.20 


8 45 


8.70 


8.95 


9. 20 


9-45 


9.70 


9.95 


to. 20 


I.I 


6.82 


7-07 


7.*2 


7-57 


.7.82 


8.07 


8.32 


8-57 


8.82 


9.07 


.9.32 


9-57 


9.82 


10.07 


10.32 


1.3 


6.04 


7.10 


7.44 


7.60 


7 -94 
8.06 


8.10 


8.44 


8.60 


8.04 


9.19 


9.44 


9.60 


9.94 


10.19 


10.44 
10. SO 


1.3 


7.06 


7.31 


7.56 


7.8. 


8.3. 


8.56 


8.81 


9. 06 


9-31 


9-S6 


9.81 


10.06 


10.31 


1-4 


7.18 


7.4J 


7.68 


7.03 


8.18 


8.43 


8.68 


8.03 


9.18 


9-43 


9.68 


9.93 


10.18 


10.43 


10.68 


I-S 


7 -30 


7-55 


7.80 


8.0s 


8.30 


8.55 


8. So 


9.05 


9 30 


9-55 


9.80 


10.05 


10.30 


10.55 


10.80 


1.6 


7.42 


7.67 


7.92 


8.17 


8.42 


8.67 


8.92 


9.17 


9-42 


9.67 


9.82 


10.17 


10.42 


10.67 


10.93 


1.7 


7-54 


7-70 


8.04 


8.20 


8.54 


8.79 


9.04 


9.20 


9-54 


9-70 


10.04 


10. 20 


10.54 


ro.79 


II .04 


1.8 


7.66 


7-91 


8.16 


8.41 


8.66 


8.91 


9.16 


9,-41 


9.66 


,9-91 


1 . 1 (, 


10.41 


1(3.66 


10.91 


11.17 


1.9 


7.78 


8.03 


8.28 


8.5.^ 


8.78 


9.03 


9.68 


.9-53 


9.78 


10.03 


10.28 


10.55 


10.78 


11.04 


II . 29 


3.0 


7.90 


8,15 


8.40 


8.65 


8.90 


9-15 


9.40 


9.65 


9.0<r 


10.15 


10.40 


10.66 


10.91 


II . 16 


II .41 


3.1 


8.02 


8.27 


8.52 


■ 8.77 


.9.02 


9.27 


9.52 


9-77 


10.02 


10:27 


10.5; 


10.78 


11.03. 


11.28 


11.53 


3.2 


8.14 


8.30 


8.64 


8.89 


9.14 


0.30 


9.64 


9 -So 


10.14 


10.39 


10.64 


10. 9D 


11.15 


11.40 


II .65 


3.3 


8.26 


8.51 


8.76 


9.01 


9.26 


9.51 


9.76 


10.01 


10. 26 


10.51 


10.76 


11.02 


11.27 


11.52 


11-77 


3.4 


8.38 


8.63 


8.88 


9.>3 


9.38 


9.63 


9. 83 


10.13 


10.38 


10.63 


10.88 


11.14 


11-39 


1 1 .64 


11-89 


a-S 


8.50 


8.75 


9.00 


9-25 


9.50 


9.75 


10.00 


10.25 


10.50 


10.75 


1 1 .00 


11. 26 


11-51 


11.76 


12.01 


3.6 


8.60 


8.87 


9.12 


9.37 


9.62 


9.87 


10.12 


10.37 


10.62 


10.87 


II .12 


11.38 


11-63 


11.88 


12. 13 


3.7 


8.74 


8.09 


9.24 


9-40 


9.74 


9.90 


10.24 


10.49 


10.74 


10.90 


II .24 


1 1. -SO 


11.75 


12.00 


12 35 


3.8 


8.86 


9. II 


9.36 


9.61 


9.86 


10.11 


10.36 


10.6! 


10.86 


1 1 . 1 1 


".37 


11.62 


fi.87 


12.12 


12.37 


3.9 


8.98 


9-23 


9.48 


9.73 


9.98 


10.23 


10.48 


10.73 


10. oS 


11.23 


11.49 


11.74 


1 1 .99 


12.24 


12.49 


30 


9.10 


9.35 


9.60 


9.85 


10. 10 


10.35 


10.60 


10.85 


11.10 


11.36 


11. 61 


11.86 


12.11 


12.36 


12.61 


31 


9.22 


9-47 


9.72 


9.97 lo. 22 


10.47 


10.72 


10.97 


11.23 


11.48 


11.73 


11.98 


12.23 


12.48 


12.74 


3-3 


9.34 


9-50 


9.84 


10.09 10.34 


10. SO 


10.84 


11.09 


11.35 


II .60 


11.85 


12.10 


12 35 


12.61 


12.86 


3-3 


9.46 


9.71 


9.96 


10. 21 


10.46 


10.71 


10.96 


11.22 


11.47 


11.72 


11.97 


12. 22 


12.48 


12.73 
12.85 


12.98 


3-4 


9.58 


9.8j 


10.08 


10.33 


10.58 


.0.83 


II .09 


11.34 


11.59 


11.84 


12.09 


12.34 


12.60 


13.10 


3-S 


9.70 


9-05 


10. 20 


10.45 


10.70 


10.95 


11.21 


1 1 .46 


II. 71 


11 .96 


12.21 


12.46 


12.72 


12.97 


13-23 


3-6 


9.82 


10.07 


10.32 


10.57 


10.82 


11.08 


11-33 


11.58 


11.83 


12.08 


12.33 


12. sS 


12.84 


13.09 


13-34 


3-7 


9-94 


10. 29 


10.44 


10.79 


10.94 


1 1 . 20 


II-4S 


11.70 


11-05 


12. 20 


12.45 


12.70 


12.96 


13.21 


13-46 


3-8 


10.06 


10.31 


10.56 


10.81 


11.06 


ii.3> 


11-57 


11.82 


12.07 


12.32 


12.57 


12.82 


13.08 


13-33 


13-58 


3-9 


10.18 


10.43 


10.68 


10.93 


II. 18 


11.44 


11.69 


11.94 


12.19 


13.44 


12.69 


12.94 


13-- 20 


13-45 


13.70 


4.0 


10.30 


10.55 


10.80 


11.05 


11.30 


11.56 


11-81 


12.06 


12.31 


12.56 


12. 81 


13.06 


13-32 


13-57 


13-83 


4-1 


10.42 


10.67 


10.92 


11.17 


11.42 


11.68 


ir.93 


12.18 


12.43 


12.68 


12.93 


13-18 


13-44 


13.69 


13-95 


4.2 


10. 54 


10.70 


II .04 


1 1 . 29 


11 .54 11.80 


12.05 


12.30 


12.55 


12.80 


13.05 


13-31 


13-56 


13-82 


14-07 


4-3 


10.60 


10.01 


1 1. 16 


11.41 


11 .66 11 .92 


12.17 


12.42 


12.67 


12.92 


13.18 


13-43 


13-68 


13-64 


14-19 


4-4 


10.78 


11.03 


11. 28 


11.53 


1 1 .78 12.04 


12.29 


12.54 


12.79 


13.04 


13.30 


13-55 


13-80 


14.06 


14.31 


4-S 


10.90 


11.15 


11.40 


n .6s 


11.90 


12.16 


12.41 


12.66 


12.91 


13.16 


13.42 


13.67 


13-92 


14.18 


14-43 


4.6 


1 1 .02 


11.27 


11.52 


11.78 


12.03 


12.28 


12.53 


12.78 


13.03 


13.28 


13.54 


13.79 


14.04 


14-30 


14-55 


4-7 


II. 14 


11.40 


II. 6s 


11. 90 


12.15 


1 2.40 


12.6s 


12.90 


IJ.IS 


13-40 


13.66 


13.91 


14.16 


14.42 


14.67 


4.8 


11.27 


11.52 


11.77 


I2.02 


12.27 


12.52 


12.77 


13-02 


13.27 


13.52 


13.78 


14-03 


14.28 


14-54 


14.79 


4.9 


11.39 


11.64 


11.89 


12.14 


12.39 


12.64 


12.89 


13.14 


13-39 


13-64 


13.90 


14. IS 


14-40 


14.66 


14-91 


S-O 


II .51 


11.76 


12.01 


12.26 


12. SI 


12.76 


13.01 


13.26 


13-51 


13-76 


14-02 


14.27 


1452 


14.78 


1S.03 


S-> 


II .63 


11.88 


12.13 


12.38 


12.63 


12.88 


13-13 


13.38 


13-63 


13-89 


14.14 


14.39 


14.64 


14.90 


15. »S 


S-2 


II .7'; 


12.00 


12.25 


12.50 


12.75 


13.00 


13-25 


13-50 


13-75 


14.01 


14.26 


14-51 


14.76 


15.02 


15.37 


S-3 


11.87 


12.12 


12.37 


12.62 


12.87 


13.12 


13-37 


13-62 


13-87 


14.13 


14.38 


14.63 


14.88 


15.14 


15.39 


5-4 


II 99 


12.24 


12.40 


12.74 


12.99 


13.24 


13-40 


13-71 


14-00 


14-25 


14.50 


14.76 


IS. 01 


IS. 26 


15. SI 


S-5 


12. II 


13.36 


12.61 


12.86 


13. II 


13.36 


13-61 


13.86 


14.12 


14-37 


14.62 


14.88 


IS. 13 


15.38 


IS. 63 


5-6 


12.23 


12.48 


13.73 


12.98 


13.23 


13.48 


13-73 


13.99 


14.24 


14-40 


14.75 


IS. 00 


IS. 35 


15.30 


IS.7S 


S-7 


12.35 


12.60 


12.85 


13.10 


13.35 


13-60 


13-85 


14.11 


14.36 


14-61 


14.87 


IS. 12 


IS. 37 


IS. 62 


15.87 


5.8 


12.47 


13.72 


13.07 


13-22 


13.47 


13-72 


1307 


14.22 


14.48 


14.74 


14.99 


IS.24 


IS.49 


IS. 74 


15-99 


5-9 


I2.S9 


13.84 


13.09 


13.34 


13-59 


13-84 


14-10 


14-35 


14.60 


14.86 


IS. II 


13.36 


IS.6i 


15.86 


16. IZ 


6.0 


13.71 


13.96 


13.31 


13.46 


13.71 


13.96 


14.32 


14.47 


i4-7i 


14.98 


iS-23 


IS. 48 


15-73 


IS. 98 


16.34 



TABLES 



213 



MUNSON AND WALKER'S TABLE FOR CALCULATING SUGARS FROM 

CUPROUS OXIDE 

(Weights in Milligrams) 



i 








Invert Sugar 
and Sucrose. 


Lactose. 


Malt 


ose. 



















s 


CJ, 

S 

0. 


t 

a 




i 
i 

a 


3 

ft rt 


c5 


i 

s 




w 

+ 

1 

a 




+ 

a 

X 
a 


a 


+ 

a 

X 
a 


i 


Q 


6 


" 


CJ 

















10 


8.9 


4.0 


A-S 


i>6 




3j8 


3.5 


4.0 


!•' 


6.3 


10 


II 


9.8 


45 


5.0 


3.1 




4is 


.4.6 


4.7 


6.7 


7.0 


It 


la 


10.7 


4.9 


54 


95 




S.I 


53 


5-4 


7.5 


7.9 


13 


13 


II .s 


5-3 


5.8 


J.O 




S.8 


1? 


6.1 


8.3 


8.7 


13 


K 


I3.4 


57 


6.3 


3 4 




6.4 


6.6 


6.8 


9.1 


9.5 


14 


IS 


1 3. "3 


6.3 


6.7 


3.9 
4.3 




7.1 


7.3 


7.5 


-9.9 


10.4 


«5 


i6 


14.3 


6.6 


7.3 




7.8 


8.0 


8.2 


10. 6 


II. 3 


16 


17 


IS-I 


7.0 


7.6 


4.8 




8.4 


8.6 


8.9 


11.4 


13.0 


17 


i8 


16.0 


7-5 


8.1 


5-3 




9.1 


9.3 


9-5 


13.3 


13.9 


t8 


19 


16.9 


7-9 


8.S 


5-7 




9.7 


10. 


10.3 


13.0 


13.7 


19 


30 


17.8 


8.3 


8.9 


6.1 




10.4 


10.7 


10.9 


13.8 


14.6 


30 


31 


18.7 


8.7 


9.4 


6.6 




II. 


II. 3 


II. 6 


14.6 


IS 4 


21 


33 


195 


9.3 


9.8 


7-0 




11.7 


12.0 


12.3 


15.4 


16.3 


33 


*3 


30.4 


9.6 


10.3 


7.5 




12.3 


12.7 


13.0 


16.3 


17. 1 


»J 


94 


31.3 


10. 


10.7 


7.9 




13.0 


13.4 


i3.7 


17.0 


17.9 


24 


as 


33.3 


10, S 


It .3 


8.4 




13.7 


14.0 


14.4 


17.8 


18.7 


'! 


36 


33.1 


10. 9' 


II. 6 


8.8 




14.3 


14.7 


IS. I 


18.6 


19.6 


36 


37 


34.0 


11-3 


12.0 


9.3 




15.0 


IS. 4 


IS. 8 


19.4 


30.4 


'I 


38 


34.9 


tl.8 


13. S 


9.7 




IS. 6 


16. 1 


16. S 


20.3 


31.2 


28 


39 


35. 8 


13.3 


13.9 


10.3 




16.3 


16.7 


17. 1 


31. 


32.1 


39 


30 


36.6 


12.6 


13.4 


10.7 


4.3 


16.9 


17.4 


17.8 


31.8 


22.9 


30 


31 


37. S 


13. I 


13.8 


II. I 


4.7 


17.6 


18. 1 


18. S 


33.6 


23.7 


3X 


3' 


38.4 


13. S 


14.3 


11.6 


s? 


13.3 


18.7 


19.3 


33.3 


24.6 


3» 


33 


393 


13-9 


14.7 


13. 


S.6 


18.9 


19.4 


19.9 


34.1 


»S.4 


33 


34 


30.3 


14.3 


IS. 3 


13. S 


6.1 


19.6 


20.1 


20.6 


34.9 


36.3 


34 


35 


31. 1 


14.8 


IS. 6 


13.9 


6.S 


20.2 


30.8 


21.3 


3S.7 


27.1 


^1 


36 


33.0 


IS. 3 


16. » 


13-4 


7.0 


20.9 


21.4 


22.0 


26. s 


37.9 


36 


37 


33.9 


IS. 6 


16. s 


13.8 


7.4 


21. S 


22.1 


22.7 


27. 3 


38,7 


n 


38 


33.8 


16. 1 


16.9 


14.3 


7.9 


22.2 


22.8 


23.4 


38.1 


39.6 


39 


34.6 


16. s 


17-4 


14.7 


8.4 


22.8 


23. S 


24.x 


38.9 


30.4 


39 


40 


355 


16.9 


17.8 


IS.i 


8.8 


23. S 


34.1 


24.8 


39.7 


31.3 


40 


41 


364 


17.4 


18.3 


IS. 6 


9.3 


24.2 


34.8 


2S.4 


«o.s 


33.1 


41 


43 


37.3 


17.8 


18.7 


16. t 


9.7 


24.8 


ss.s 
20.2 


26.1 


31.3 


'*-2 


4* 


43 


38.3 


18.3 


19.3 


16.6 


10.3 


2S.S 


26.8 


32.1 


33.8 


4) 


44 


39.1 


18.7 


ig.o 


17. 


10. 7 


36.1 


36.8 


27. S 


33.9 


34.6 


44 


45 


40.0 


19. 1 


30.1 


17. 5 


II. t 


26.8 


27. S 


28.2 


33.7 


35. 4 


*l 


46 


40.9 


19.6 


20. s 


17.9 


II. 6 


27.4 


28.2 


28.9 


34.4 


36.3 


46 


47 


41-7 


30. 


21 .0 


18.4 


13 .0 


28.1 


28.9 


29.6 


35-3 


37.1 


*l 


48 


43.6. 


30.4 


31.4 


18.8 


I3.S 


28.7 


39. s 


30.3 


^!S 


32S 


48 


49 


43 S 


30.9 


31.9 


19.3 


13.9 


29.4 


30,2 


31.0 


36.8 


38.8 


49 


SO 


44-4 


31.3 


33.3 


19.7 


13. 4 


30.1 


30.9 


31.7 


37.6 


39.6 


50 


SI 


453 


31.7 


33.8 


30.3 


13.9 


30.7 


31. s 


32.4 


38.4 


40.4 


51 


51 


46.3 


32.3 


33.3 


30.7 


14.3 


31.4 


32.2 


33.0 


39.3 


41.3 


5* 


53 


47.1 


33.6 


33.7 


31. I 


14.8 


3i.i 


32.9 


33.7 


40.0 


43.1 


53 


54 


48.0 


33.0 


34-t 


31.6 


IS. 3 


32.7 


33.6 


34.4 


40.8 


43.9 


54 


SS 


48.9 


33.5 


34.6 


33.0 


IS. 7 


33.4 


34.3 


35.1 


41.6 


43.8 


S| 


S6 


49-7 


339 


35.0 


22. S 


16.2 


34-0 


34.9 


3S.8 


43.4 


44.6 


56 


57 


50.6 


34.3 


35.5 


22.9 


16.6 


34-7 


3S.6 


36. S 


43. a 


45-4 


11 


S8 


Si-S 


34.8 


359 


23-4 


17.1 


35.4 


36.3 


37.2 


44 


46.3 


S9 


S3. 4 


3S.3 


36.4- 


33.9 


«7.S 


36,0 


37.0 


37.9 


44.8 


47.x 


59 


6o 


S3. 3 


3S.6 


36.8 


34. 3 


18.0 


36.7 


37.6 


38.6 


4S.6 


48.0 


60 


6i 


54.3 


36.1 


37.3 


34.8 


18. S 


37.3 


38.3 


39.3 


46.3 


48.8 


61 


63 


SSI 


36. s 


37.7 


2S.3 


18.9 


38.0 


39 


40.0 


47.1 


49-6 


63 


63 


S6.6 


370 


38.3 


35.7 


19.4 


33.6 


39.7 


40.7 


47.9 


50. S 


63 


64 


.56.8 


a7.4 


38.6 


36,1 


19.8 


».3 


40.3 


41.4 


48.7 


51.3 


64 



214 



APPENDIX 



MUNSON AND WALKER'S TABLE FOR CALCULATING SUGARS FROM 

CUPROUS OXIDE— (Coniimied) 

(Weights in Milligrams) 



q 








Invert Sugar 
and Sucrose. 


Lactose. 


Maltose. 


d 


3 
















3 


c^ 






















L) 


t) 








"rt 


„ 




Q 


d 







4) 


1 

1 


1 


^ 


1 
> 


2 s, 


2 

6S, 





+ 

6 


+ 

s 


3 


+ 

6 


•0 


3 


3 


1 



i 


0^ 


2^ 
c5w 


n 

X 

£3 


a 


a 






S 

a 

3 


O 





Q 




d 


" 











6 








6$ 


57-7 


27.8 


29.1 


26.6 


20.3 


40.0 


41.0 


42.x 


49-5 


52.1 


6s 


66 


58.6 


28.3 


29-5 


27.1 


20.8 


40.6 


41.7 


42.8 


SO. 3 


53 


66 


67 


S9S 


28.7 


30.0 


27-5 


21.2 


41.3 


42.4 


43. s 


SI. I 


53.8 


67 


68 


60.4 


29.2 


30.4 


28.0 


21.7 


41.9 


43.1 


'44.2 


. 51.9 


54.6 


68 


69 


61.3 


29.6 


30.9 


28. S 


22.2 


42.6 


43.7 


.44-8 


52.7 


55. 5 


69 


70 


62.1 


30.0 


31.3 


28.9 


22,6 


43-3 


44.4 


45. S 


53-5 


56.3 


70 


7« 


63.1 


30. 5 


31.8 


29.4 


23.1 


43.9 


45.1 


46.2 


54.3 


57-1 


71 


7* 


64.0 


30.9 


32.3 


29.8 


23. s 


44.6 


45.8 


46.9 


55-1 


58.0 


72 


73 


64. S 


31-4 


32.7 


30.3 


24.0 


45.2 


46.4 


47.6 


SS-9 


58.8 


73 


74 


65.7 


31.8 


33-2 


36.8 


24.5 


45-9 


47.1 


48.3 


56.7 


59.6 


74 


7S 


66.6 


32.2 


33.6 


31.2 


24.9 


46.6 


47.8 


49.0 


57. S 


60.5 


75 


76 


67.5 


32.7 


34.1 


31.7 


25.4 


47.2 


48. 5 


49.7 


S8.2 


61.3 


76 


'Z 


68.4 


33 1 


34-5 


32.1 


2S.9 


47.9 


49.1 


50.4 


590 


62.1 


77 


78 


69 -3 


33.6 


3SO 


32.6 


26.3 


48.5 


49.8 


51. 1 


1'! 


63.0 


78 


79 


70.2 


34-0 


35-4 


33-1 


26.8 


49.2 


SO. 5 


SI. 8 


60.6 


63.8 


79 


8o 


71. 1 


34-4 


35-9 


33-5 


27-3 


49-9 


SI. 2 


52. S 


61 .4 


64.6 


80 


8t 


71.9 


34-9 


36.3 


34.0 


27.7 


50.5 


51.9 


53.2 


62.2 


6s.S 


81 


82 


72.8 


35-3 


36.8 


345 


28.2 


51.2 


52. 5 


53.9 


63.0 


66.3 


82 


83 


73-7 


35-8 


37-3 


34-9 


28.6 


51.8 


53-2 


54.6 


63.8 


67.1 


83 


84 


74.6 


36.2 


37.7 


35-4 


29. 1 


52-5 


53-9 


55-3 


64-6 


68.0 


84 


8S 


75 -S. 


36.7 


38.2 


35.8 


29.6 


53- 1 


54.6 


56.0 


65.4 


68.8 


8S 


86 


76.4 


37.1 


38.6 


36.3 


30.0 


53.8 


55-2 


56.6 


66.2 


69 -7 


86 


87 


77-3 


37-5 


391 


36.8 


30. S 


545 


55.9 


57. 3 


67 .0 


70.5 


87 


88 


78.2 


38.0 


39-5 


37.2 


31.0 


55.1 


S6.6 


58.0 


67.8 


71.3 


88 


89 


79.1 


38.4 


40.0 


37.7 


31.4 


55.8 


57.3 


S8.7 


68.5 


72.2 


89 


90 


79-9 


38.9 


40,4 


38.2 


31.9 


S6.4 


58.0 


59.4 


69 -3 


73.0 


90 


9' 


80.8 


39-3 


40.9 


38.6 


32.4 


57. 1 


58.6 


60.1 


70.1 


73.8 


91 


92 


81.7 


39.8 


41-4 


391 


32.8 


57.8 


59-3 


60.8 


70.9 


74. V 


92 


93 


82.6 


40.2 


41.8 


39-6 


33.3 


58.4 


60.-0 


61.5 


71-7 


75. S 


93 


94 


83.5 


40.6 


42.3 


40.0 


33.8 


59. 1 


60.7 


62.2 


72. S 


76.3 


94 


95 


84.4 


41. 1 


42.7 


40. 5 


34.2 


59.7 


61:3 


62.9 


.73.3 


77.2 


9| 


96 


85.3 


41-5 


43-2 


41.0 


34.7 


60.4 


62.0 


63.6 


74.1 


78.0 


96 


97 


86.2 


42.0 


43.7 


41.4 


35-2 


61. 1 


62.7 


64.3 


74.9 


78.8 


97 


98 


87.1 


42.4 


44 I 


41.9 


3S-6 


61.7 


63.4 


65.0 


75.7 


79.7 


98 


99 


87.9 


42.9 


44 .-6 


42.3 


36.1 


62.4 


64.0 


65.7 


76. 5 


80. S 


99 


Too ' 


.88.8 


43-3 


45.0 


42.8 


36.6 


63.0 


64.7 


66.4 


77.3 


81.3 


ibo 


lOI 


89.7 


43-8 


45-5 


43.3 


37.0 


63.7 


65.4 


67.1 


78.1 


82.1 


lOI 


lOJ 


90.6 


44.2 


46.0 


43-8 


37. 5 


64.4 


66.1 


67.8 


78.8 


83.0 


loa 


103 


91S 


44.7 


46.4 


44.2 


38.0 


65.0 


66.7 


68.5 


79.6 


83.8 


103 


104 


92.4 


45.1 


46.9 


44.7 


38.5 


65.7 


67.4 


69. 1 


80.4 


84.7 


104 


los 


,93 -3 


45-5 


47-3 


45. > 


38.9 


66.4 


68.1 


69.8 


81.2 


85. s 


los 


106 


94.2 


46.0 


47-8 


45.6 


39.4 


67.0 


68.8 


70. 5 


82 .0 


86.3 


106 


107 


95 


46.4 


48.3 


46.1 


39-9 


67.7 


69 S 


71.2 


82 .8 


87.2 


107 


108 


95-9 


46.9 


48.7 


46.6 


40.3 


68.3 


70.1 


71.9 


83.6 


88.0 


108 


109 


96.8 


47-3 


49-2 


47.0 


40.8 


69.0. 


70.8 


72.6 


84.4 


88.8 


100 


JIO 


97-7 


47.8 


49-6 


47-5 


41-3 


69.7 


71. 5 


73.3 


85.2 


89.7 


no 


III 


98.6 


48.12- 


50.1 


48.0 


41.7 


70.3 


72.2 


74.0 


86.0 
86.8 
87.6 
88.4 


90. 5 


III 


112 


99-5 


48.7 


50.6 


48.4 


42.2 


71.0 


72.8 


74.7 


91.3 


112 


113 


100.4 


49- 1 


51.0^ 


48.9 


42.7 


71.6 


73.5 


75.4 


92 .2 


113 


114 


loi .3 


49-6 


5I-S 


49.4 


43-2 


73.3 


74-2 


76.1 


930 


114 


"S 


102.2 


SO.O 


SI. 9 


49-8 


43.6 


73-0 


■74.9 


76.8 


89.2 


93.9 


IIS 


116 


103.0 ' 


50.5 


52.4 


50.3 


44.1 


73.6 


75.6 


77. S 


90.0 


94.7 


116 


117 


103.9 


SO -9 


52.9 


SO. 8 


44.6 


74.3 


76.2 


78.2 


90.7 


95. 5 


117 


118 


104.8 


51-4 


53-3 


51.2 


45-0 


7S.0 


76.9 


78.9 


91-5 


96.4 


118 


119 


105.7 


St. 8 


53.8 


51.7 


45. S 


75.6 


77.6 


79.6 


93-3 


97.2 


119 



TABLES 



215 



MUNSON AND WALKER'S TABLE FOR CALCULATING SUGARS FROM 
CUPROUS OXIDE— {Conlinued) 

(Weights in Milligrams) 



o 
3 








Invert Sugar 
and Sucrose. 


Lactose. 




Maltose. 


1 














d 







6 


■o 






u . 


5 



S 




X 


K 




w 


1 


•R 


"a 




00 


t- 


H 




+ 


+ 




+ 





O 
1 




u 

■0. 

a. 


£ 

a 


3 
W 

> 


h 

,03 


h 


i 


i 


1 









6 


d 


a 


d 


" 











c 





u 


X30 


X06.6 


52-3 


54.3 


52-2 


46.0 


76.3 


78.3 


80.3 


93-1 


98.0 
98.9 


120 


131 


10-7.5 
108.4 
109-3 

IXO. I 


52 .7 


54-7 


52.7 


46.5 


76 - 9; 


79-0 


81.0 


93.9 


I2X 


133 


53-2 


55.2 


53-1 


46.9 


77.6 


79-6 


81.7 


94-7 


99.7 


X22 


123 

"4 . 


S3 - 6 
54-1 


55.7 
S6.i 


53-6 
54.1 


47-4 
47-9 


78.3 
,78.9 


80.3 
61.0 


82.4 
83.1 


9S-5 
96.3 


100. 5 
101.4 


123 
124 


126 


III .0 


54. S. 


56.6 


54. 5 


48.3 


79.6 


81.7 


83.* 


97.1 


ioa.2 


12s 
126 


XIX .9 

112. 8 


55.0 


57.0 


55-0 


48.8 


80.3 


82.4 


84-S 


97-9 


loslo 


127 
128 


55-4 


57-5 


55-5 


49-3 


80.9 


830 


85-2 


98.7 


103.9 


127 
128 


II3-7 
XI4-6 


55-9 


58.0 


55-9 


49-8 


81.6 


83-7 


85-9 


99-4 


104-7 


<39 


56.3 


58.4 


56-4 


50.2 


82.2 


84-4 


86.6 


XO0.3 


105-5 


T29 


130 
131 
132 
133 

134 


iiSS 
116. 4 
XI7-3 
X18.X 


56-8 
57.2 

58. f 


58.9 
59-4 
59-8 
60.3 


56-9 
57-4 
57-8 
58.3 


SO. 7 
51.2 
51.7 

52. X 


82.9 
83.6 
84.2 
84.9 


85. 1 
85.7 
86.4 
87-1 


87-3 
88.0 
88.7 
89-4 


xoi .0 
101.8 
X02.6 
103.4 


106.4 
107.2 
108.0 
108.9 


130 

I3< 
132 
133 


119. 


S8.6 


60.8 


58.8 


S2.6 


85. S 


-87.8 


90. 1 


X04.3 


X09.7 


U4 


I3S 
136 

138 
139 


XT9.9 


59.0 


61.2 


59-3 


S3. 1 


86.2 


88. S 


90.8 


XOJ.O 


xio.s 


I3S 
136 


120.8 


59-5 


61.7 


59-7 


53.6 


86.9 


89. 1 


91. S 


X0S.8 


III. 4 


121. 7 
X22 .6 


60.0 


62.2 


60.2 


54-0 


87. S 


89.8 


92.1 


106.6 


112.2 


X38 


60.4 


62.6 


60.7 


54. S 


88.3 


90. S 


92.8 


107.4 


113 -0 


123.5 


60.9 


63.x 


61.2 


SS-o 


88.9 


91.3 


93. S 


X08.2 


113.9 


139 


X40 


124.4 


61.3 


63.6 


61.6 


55. S 


89. S 


91.9 


94.2 


109.0 
109. 8 


114.7 


X40 


141 


X2S . 3 


61.8 


64.0 


62.x 


559 


90.2 


92. S 


fl4-9 


115-5 
116.4 


141 


142 


X26.-I 


62.2 


64.5 


62.6 


S6-4 


90.8 


93.2 


95-6 


110.5 


X42 


X43 


127.0 


62.7 


65.0 


63.x 


SO -9 


91-S 


93 9 
94-0 


96.3 


III. 3 


X17-2 
X18.0 


143 


144 


X27.9 


63.1 


65.4 


63. S 


57.4 


92.2 


97.0 


112. I 


144 


145 


X28.8 


63.6 


65-9 


64.0 


57. 8 


92.8 


958 


97-7 


XX2.9 


T18.9 


145 
X46 


146 
147 


129. 7 


64.0 


66.4 


64-S 


S8.3 


93-5 


959 


98.4 


113.7 


119-7 


130.6 


64-5 


66.9 


65.0 


58.8 


94.2 


96.6 


99-1 


114-S 


120.5 


147 
148 


148 


i3f.S 
X33-4 


65.0 


67.3 


65.4 


59-3 


94-8 


97.3 


99-8 


115-3 


121 .4 


149 


65.4 


67.8 


65-9 


59-7 


95. S 


98.0 


100. 5 


X16. X 


X22 .2 


149 


150 


133 -2 


65.9 


68.3 


66.4 


60.2 


96.1 


98.7 


101.2 


116. 9 


123.0 


ISO 


151 

IS2 

153 
'54 


134- 1 


66.3 


68.7 


66.9 


60.7 


96.8 


99.3 


I0I.9 


X17-7 


123-9 


151 


135 -O 


66.8 


69.2 


67-3 


61.2 


97 -S 


100. 


102.6 


ii9.S 


124. 7 


152 


135.9 


67.2 


69.7 


67.8 


61.7 


98.1 


100.7 


103.3 


X19-3 


12S-5 
126.4 


153 


136.8 


67.7 


70.1 


68.3 


62.x 


98.8 


ipi.4 


104.0 


X20.0 


154 


15s 
156 
157 
158 


137 . 7 


68.2 


70^6 


68.8 


62.6 


99- S 


102. 1 


104.7 


120.8 


127.2 
128.0 
128.9 
129-r 


is's 

156 


138.6 


68.6 


71. 1 


69.2 


63-1 


100. 1 


102.8 


10S.4 


121 .6 


1395 
140.3 


69.1 
69. s 


71.6 
72.0 


69-7 
70.2 


63-6 
64-1 


100.8 
lOI.S 


103.4 
104. 1 


106. 1 
106.8 


122.4 

X23.a 


157 
158 


159 


141. 2 


70.0 


72. S 


70.7 


64. S 


102. I 


104.8 


107. S 


X24.0 


130. 5 


159 


160 
161 


142. X 
143 .0 


70.4 
70.9 


73.0 
73-4 


71.6 


65.0 
65-5 


102.8 
103-4 


105. S 
106.2 


108.2 
108.9 


124.8 
H5-6 


131-4 
132.2 


160 
161 
i6» 
163 
164 


162 
163 
164 


143-9 
144.8 
X4S-7 


71-4 
71.8 

n-3 


73-9 
74-4 
74-9 


72.1 
72.6 
73 -X 


66.0 
66.5 
66.9 


104. t 
104.8 
IOS.4 


106.8 
107. 5 
108.2 


109.6 
no. 3 

Ilt.O 


126. 4 

X27.» 

128.0 


133 
133 9 
134-7 


j6s 
166 


J46.6 
147 . 5 


72.8 
73 • 2 


75-3 
75-8 


73-6 
74.0 


67-4 
67.9 


106. T 
106.8 


108.9 
i09.6 


III. 7 
112.4 


128.8 
129.6 


135 5 
136.4 


x6s 
166 
167 
x68 
169 


167 


148.3 


73-7 


76-3 


74-5 


68.4 


107.4 


110.3 


1131 
113. 8 
114-S 


130.3 


1J7- 2 


168 
169 


149.2 
150.1 


74-6 


76.8 
77-2 


75-0 
75-5 


68.9 
69-3 


108.. 
108.8 


110.9 
III. 6 


131-1 
13IJ9 


13..- 
138.9 


X70 


ISI -o 


75- 1 


77.7 


76.0 


69.8 


109.4 


112. 3 


11S.2 


132-7 


139-7 


170 


171 

172 


xsi .9 


75-5 


78.2 


76.4 


70.3 


110. I 


113. 


115-9 


133-S 


140- S 


X71 


152 .8 


76.0 


78.7 


76.9 


70.8 


no. 8 


113-7 


116. 6 


134-3 


141-4 


I7» 


173 
174 


153.7 
154-6 


76.4 
76.9 


79-1 
79-6 


77-4 
77-9 


71-3 
71-7 


III. 4 
113. I 


114-3 
115. 


117. 3 
118. 


135-1 
1359 


142.2 
143.0 


»7J 
174 



216 



APPENDIX 



MUNSON AND WALKER'S TABLE FOR CALCULATING SUGARS FROM 

CUPROUS OXIDE— {Contiftiied) 

(Weights in Milligrams) 



o 








Invert Sugar 
and Sucrcse. 


Lactose. 


Malt 


ose. 





3 
















3 


<^ 

















































i 

•a 
o 

3 


3' 







3 

d 


■5 


a 



+ 

6 


<2 
+ 
6 


d 


d 

+ 

d 


4) 

a 




p 


1 


u 


■s 


a u> 


it 


n 


u 


n 


n 





o 




1 


C 3 

(5w 





K 
s 



d 


W 
S 


K 


0. 
z) 



I7S 


ISS-S 


77-4 


80.1 


78.4 


72.2 


112. 8 


IIS. 7 


118.7 


136.7 


143-9 


17^ 


176 


156.3 


77-8 


S(X>6 


78-8 


72.7 


113. 4 


116.4 


119. 4 


137.5 


144-7 


176 


177 


157-3 


78.3 


81.0 


79-3 


73-a 


114. 1 


117. 1 


120.1 


138.3 


145-5 


177 


178 


158. 1 


78.8 


81.5 


79-8 


73-7 


114. 8 


117. 8 


120.8 


139. 1 


146.4 


17S 


179 


159.0 


79.3 


83.0 


80.3 


74-3 


IIS. 4 


118.4 


121. s 


139-8 


147.2 


179 


180 


159. 9 


79-7 


83.5 


80.8 


74.6 


116. 1 


119. 1 


122.2 


140.6 


148.0 


180 


181 


160.8 


80. 1 


82.9 


81.3 


75-1 


116.7 


119.8- 


122.9 


141. 4 


148.9 


181 


182 


161 .7 


80.6 


83.4 


81.7 


75-6 


II7-4 


120.5 


123.6 


142.3 


149-7 


182 


183 


162.6 


81. 1 


83 -9 


82.3 


76.1 


118. 1 


121 . 2 


124.3 


"143.0 


I SO -5 


183 


184 


163.4 


81.5 


84.4 


83.7 


76.6 


118.7 


121. 8 


125.0 


143.8 


151-4 


184 


l8s 


164.3 


83.0 


84.9 


83.3 


77.1 


H9-4 


122. s 


125.7 


144.6 


152-2 


185 


186 


165.3 


83.5 


85-3 


83-7 


77.6 


120. 1 


123.2 


126.4 


145.4 


153-0 


186 


187 


166. 1 


83.9 


85.8 


84.2 


78.0 


120.7 


123.9 


127.1 


146. 3 


1S3-9 


187 


1 83 


167.0 


83.4 


86.3 


84.6 


78.5 


121. 4 


124.6 


127.8 


147-0 


154-7 


188 


189 


167.9 


83.9 


86.8 


8s. 1 


79.0 


122. 1 


12s. 3 


128 S 


147-8 


iSS-S 


189 


190 


168.8 


84.3 


87.3 


85-6 


79. S 


122.7 


125.9 


129.2 


148.6 


156.4 


190 


191 


169.7 


84.8 


87.7 


86.1 


80.0 


123.4 


126.6 


129.9 


149-3 


1S7.2 


191 


193 


170.5 


85-3 


88.2 


86.6 


80. 5 


124. 1 


127.3 


130.6 


ISO- 1 


158-0 


19? 


193 


l1l-4 


85-7 


88.7 


87.1 


81.0 


124-7 


128.0 


131.3 


150.9 


158.9 


19., 


194 


173.3 


86.3 


89.3 


87.6 


81.4. 


125-4 


128.7 


132.0 


151-7 


159.7 


194 


19$ 


»73.a 


86.7 


89.6 


88.0 


81.9 


126. 1 


129.4 


132.7 


152-5 


160. 5 


I9S 


196 


174. 1 


87.1 


90. 1 


88.5 


82.4 


126.7 


130.0 


133.4 


IS3-3 


161 .4 


196 


197 


175.0 


87-6 


90.6 


89-0 


83.9 


127.4 


130.7 


134.1 


IS4-I 


162 .2 


197 


198 


J7S.9 


88.1 


91-1 


89-5 


83.4 


128. 1 


131. 4 


134.8 


154-9 


l6j.o 


198 


199 


176.8 


88.5 


91 .6 


90.0 


83.9 


128.7 


132. 1 


• 135. S 


lSS-7 


163.9 


199 


300 


177.7 


89.0 


92.0 


90.5 


84.4 


129.4 


132.8 


136.2 


156.5 


164.7 


300 


aoi 


178.5 


89-S 


92. S 


91 .0 


84.8 


130.0 


133. S 


136.9 


157.3 


165.5 


30I 


303 


179-4 


89.9 


930 


91-4 


85. 3 


130.7 


134.1 


137.6 


158. 1 


166.4 


3oa 


303 


180.3 


90.4 


J>3-5 


91.9 


85.8 


131.4 


134.8 


138.3 


158.8 


167.3 


303 


304 


181. 3 


90.9 


94.0 


93.4 


86.3 


132.0 


I3S.S 


139.0 


159-6 


168.0 


304 


305 


18]. I 


91.4 


94. S 


93.9 


86.8 


132.7 


136. 2 


139.7 


160.4 


168.9 


305 


ao6 


183.0 


91.8 


94.9 


93-4 


87.3 


133-4 


136.9 


140.4 


161 . 3 


169-7 


300 


307 


183.9 


93-3 


95-4 


93-9 


87.8 


134-0 


137.6 


141. 1 


162.0 


170.5 


307 


308 


184.8 


93-8 


95-9 


94-4 


88.3 


134-7 


138.3 


141.8 


162.8 


171.4 


208 


309 


185.6 


93 -a 


96.4 


94.9 


88.8 


135-4 


138.9 


142. S 


163.6 


173.3 


209 


aio 


186. 5 


93-7 


96.9 


9$. 4 


89-3 


136 ."0 


139.6 


143.2 


164.4 


173 


210 


311 


187.4 


94 3 


97.4 


95-8 


89.7 


136.7 


140.3 


143.9 


165.3 


173.8 


2H 


313 


188.3 


94-6 


97-8 


96.3 


90.3 


137-4 


141.0 


144.6 


166.0 


174.7 


313 


313 


f89.2 


95-1 


98-3 


96.8 


90.7 


138.0 


141.7 


14s. 3 


166.8 


175-5 


213 


314 


J90. 1 


95-6 


98.8 


97-3 


91.3 


138.7 


142.4 


146.0 


167.5 


176.4 


314 


ais 


191 .0 


96.1 


99>i 


97.8 


91-7 


13* .4 


143.0 


146.7 


168.3 


177.3 


3I| 


316 


191 9 


96.5 


99.8 


98.3 


93.3 


140.0 


.143.7 


147.4 


169. 1 


178.0 


3l6 


317 


193.8 


97.0 


100 .3 


98.8 


93.7 


140.7 


144.4 


148.1 


169.9 


178.9 


317 


3l8 


193-6 


97-5 


100.8 


99-3 


93. a 


141.4 


145.1 


148.8 


170-7 


179.7 


2l3 


319 


194 -S 


98.0 


loi .3 


99 8 


93.7 


143.0 


143-8 


149. S 


171. 5 


180.5 


319 


330 


I9S-4 


98.4 


101.7 


100-3 


94.* 


142.7 


146- S 


150.2 


173.3 


181.4 


320 


331 


196.3 


98.9 


103.3 


100.8 


94.7 


143.4 


147-2 


150.9 


173.1 


182.3 


331 


333 


197-3 


99-4 


I03 .7 


lOI .3 


95.1 


144.0 


147-8 


151.6 


173-9 


183.0 


333 


333 


198. I 


99-9 


103.3 


101.7 


95-6 


144.- 7 


148. S 


isa.3 


174-7 


183.9 


333 


334 


199-0 


100.3 


103-7 


103.3 


96. 1 


14s -4 


149.2 


153.0 


175-5 


184.7 


334 


335 


199 9 


100.8 


104.3 


103.7 


96.6 


146.0 


149.9 


153.7 


176.3 


*!l-5 


335 


336 


300.7 


iqi-3 


104.6 


103.3 


97.1 


146-7 


150.6 


154-4 


177.0 


186.4 


326 


337 


30I .6 


101.8 


105. 1 


103.7 


97.6 


147.4 


ISI.3 


155-1 


177.8 


187.3 


227 


338 


303. 5 


103 .3 


105.6 


104.3 


98. 1 


148.0 


152.0 


155.8 


178.6 


188.0 


228 


339 


303.4 


103.7 


106. 1 


104.7 


98.6 


148.7 


152.6 


156-S 


179.4 


188.8 


339 



TABLES 



217 



MUNSON AND WALKER'S TABLE FOR CALCULATING SUGARS FROM 

CUPROUS OXIDE— {Conlinued) 

(Weights in Milligrams) 



i 








Invert Sugar 
and Sucrose 


Lactose. 


Maltose. 


i 



















o. 








_ 






d 


d 




d 


u 


e 






i 

BO 


5 



•3 

1 




X 

•*> 


(2 




•4 

X 




■R 


9 




H 




+ 


+ 




+ 





o 


0, 

0. 


8 
g 


3 
1 


is 


11 


a 

X 





1 

9 


3 


3 

53 
a 


a 

3 


9 


cS 


Q 


c 


6 


« 


6 

















230 


204 -3 


103.3 


106.6 


105.3 


99:1 


149-4 


153.3 


157-2 


180.2 


189.7 


230 


231 


205 .2 


10^.7 


107 - ' 


105.7 


99-6 


150.0 


1540 


1579 


181 .0 


1 90.- 5 


231 


232 


206.x 
207 .0 


104- 1 


107 .6 


106.2 


100. 1 


150.7 


154-7 


158.6 


181. 8 


191-3 


232 


233 

234 


J04.6 


108. 1 


106.7 


100.6 


151.4 


155-4 


159.3 


183.6 


193.3 


233 


207.9 


105. 1 


108-6 


107.3 


101 . 1 


152.0 


156. 1 


160.0 


183.4 


193-0 


334 


23s 

236 

237 

238 

239 


208.7 


105.6 


109. 1 


107.7 


rot. a 


152.7 


156.7 


160.7 


184.2 


193-8 


"1 


309.6 


106.0 


109.5 


108.2 


103. 1 


153. 4 


157.4 


161. 4 


184.9 


194-7 


236 


210. 5 


106. 5 


IIO.O 


108.7 


102 .6 


154-0 


158. 1 


162.1 


185.7 


195-5 


237 


211 .4 


107.0 


110.5 


109.2 


103.1 


154-7 


158.8 


162.8 


186.5 


196.3 


238 


312.3 


107-5 


III.O 


109.6 


103.5 


155-4 


159. S 


163. S 


187.3 


197.2 


239 


240 
241 


213.2 
2M.I 


108.0 


111. 5 


IlO.l 


104.0 


156. 1 


j6o;2 


164.3 


188.1 


198.0 


240 


108.4 


113. 


110.6 


104. 5 


156.7 


160:9 


165.0 


188.9 


198.8 


241 


242 

243 


215.0 
215.8 


108.9 


113.5 


III .1 


105.0 


157.4 


161.S. 


16S-7 


189-7 


199-7 


242 


109.4 


113-0 


iir.6 


105. i 


158.1 


162.2 


166.4 


190.5 


200.5 


243 


244 


216.7 


109-9 


113-S 


112. 1 


106.0 


158.7 


162.9 


167. 1 


191.3 


201.3 


244 


245 
246 
247 


217.6 


no. 4 


114.0 


112. 6 


106.5 


159. 4 


163.6 


167.8 


192. 1 


202.2 


24s 


218.5 


no. 8 


114.5 


1I3-I 


107.0 


160.1 


164.3 


168. S 


192.9 


203 .0 


246 


319.4 


III .3 


115.0 


113-6 


107.5 


160.7 


165.0 


169.2 


193-6 


203.8 


247 
3 48 


248 


320.3 


m -8 


115-4 


114-1 


108.0 


161.4 


165.7 


169.9 


194-4 


204.7 


249 


231.2 


112. 3 


liS-9 


114.6 


108. 5 


162.1 


166.3 


170.6 


195-2 


205.5 


?49 


250 

2SI 
253 

253 


3 3 2.1 


112. 8 


116. 4 


itS-i 


109.0 


162.7 


167.0 


171-3 


196.0 


206.3 


3 50 


333.0 
323-8 

324. 7 


113. 2 


116.9 


115-6 


109.5 


163.4 


167.7 


172.0 


196.8 


207.2 


351 


113-7 


117.4 


116. 1 


IIO.O 


164. 1 


168.4 


172.7 


197-6 


208.0 


352 


114-2 


117.9 


116.6 


110.5 


164.7 


169.1 


173. 4 


198.4. 


208.8 


253 


254 


325.6 


114-7 


118.4 


117.1 


III .0 


165.4 


169.8 


174-I 


199.2 


209.7 


254 


256 

257 


226. s 
327.4 
228.3 


IIS-2 


118. 9 


117.6 


iii.S 


166. 1 


170. s 


174-8 


300.0 


210.5 


'^1 


115.7 


119.4 


118. 1 


112 .0 


166.8 


171. 1 


17S-S 


300.8 


211 ,3 


356 


116.1 


119.9 


118.6 


112.5 


167.4 


171. 8 


176.2 


201.6 


212. 2 


258 


259 


329.3 


116. 6 


130.4 


119. 1 


113-0 


168. 1 


172. S 


176.9 


202.3 


213,0 


330. 1 


117. 1 


120.9 


119.6 


113. S 


168.8 


173-2 


177-6 


203.1 


313.8 


259 


360 


331 .0 


it7.6 


131. 4 


120. t 


114.0 


169.4 


173.9 


178.3 


203.9 


314.7 


260 


36x 


231 .8 


118. 1 


131. 9 


120.6 


114.5 


170. 1 


174-6 


179.0 


204.7 


215-S 


261 
262 


363 


2^2 . 7 


118. 6 


133 .4 


121. 1 


115.0 


170.8 


175-3 


179.8 


205.5 


216-3 


361 


233 .6 


119. 


122.9 


121 .6 


1155 


171. 4 


176.0 


180.5 


206.3 


217-2 


263 


264 


234-5 


119. 5 


123.4 


122. 1 


116.0 


172. 1 


176.6 


181. 3 


207.1 


218.0 


264 


26s 

266 


235-4 
336.3 


130.0 


123.9 


123.6 


116. S 


172.8 


177.3 


181. 9 


207.9 


218.8 


26s 


I30.5 


124.4 


123.1 


117.0 


173. S 


178.0 


182.6 


208.7 


219-7 


266 
367 
368 
369 


367 


337.3 


121 .0 


124.9 


123.6 


117-S 


174-1 


178.7 


183.3 


209. 5 


330-5 


368 


238.1 


131 .5 


135.4 


124.1 


118.0 


174.8 


179.4 


184.0 


210.3 


331.3 


269 


238.9 


132. 


125.9 


124.6 


118. S 


175-S 


180.1 


184-7 


211.0 


222.1 


270 


239.8 


122. S 


126.4. 


125.1 


119.0 


176. 1 


180.8 


185-4 


211.8 


233.0 


37a 


27L 
372 
273 
274 


240. 7 


122.9 


126.9 


125.6 


119-S 


176.8 


181. 5 


186.1 


212.6 


233.8 


27)1 


341 .6 


123.4 


127.4 


136.2 


120.0 


177. S 


182. 1 


186.8 


213-4 


224.6 


37« 


343.5 
343-4 


123-9 
124.4 


127.9 
128.4 


136.7 
137.2 


120.6 

121.1 


178.1 
178.8 


182.8 
183.5 


187. S 
188.3 


214.2 
215.0 


225-5 
326.3 


273 

274 


276 


244-3 
245.2 


124-9 

135.4 


138.9 
139.4. 


127.7 
128.2 


121. 6 
133. I 


179. S 

180.2 


184-2 
1849 


188.9 
189.6 


215.8 
216.6 


227.1 
228-0 
238-8 

339.6 


»7S 

276 


277 
278 


246.1 
246.9 


135-9 

136.4 


139.9 
130.4 


138.7 
139.2 


133.6 
123.1 


180.8 
181. S 


18S.6 
18^.3 


190.3 
19IJO 


217-4 
318.2 


277 
278 


279 


247.8 


136.9 


130.9 


129.7 


123.6 


183.2 


187.0 


191-7 


318.9 


330. 5 


2 7» 


280 


248.7 


137.3 


131-4 


130.2 


124. t 


182.8 


187.7 


192.4 


219.7 


231.3 


280 
281 
281 
28J 

284 


38t 


249.6 


137.8 


131 .9 


130-7 


124.6 


183. s 


188.3 


193.1 


220.5 


232.. I 


282 


250^5 


138.3 


133 .4 


131-2 


125.1 


.184.2 


189.0 


193.9 
194.6 


221.3 


233.0 
233.8 


383 


251 ,4 


138.8 


133.9 


131.7 


125.6 


184.8 


189.7 


233.1 


284 


252.3 


139.3 


133-4 


.133.2 


126.1 


I8s-S 


190.4 


195-3 


332,9 


234,6 



218 



APPENDIX 



MUNSON AND WALKER'S TABLE FOR C.\LCULATING SUGARS FROM 

CUPROUS OXIDE— (Continued) 

(Weights m Milligrams) 



q 








Invert Sugar 
and Sucrose. 


Lactose. 


Maltose. 





1 
















3 
(3 


V 








'ti 


_ 







d 




d 




•o 
O 


3 



<! 


00 

3 


6u 


« 




+ 


-f 




+ 


•c 
•R 



3 


u 







.rt ca 


grt 


6 


6 


6 


d 


d 


3 


s. 

a 

3 
O 


0. 
a 



i.1 


> 

c 

H- 1 


0^ 
6 




u 


X 
6 


=5 



X 



1 


s 

a 
3 



285 


253-2 


129.8 


133.9 


132.7 


126.6 


186.2 


191. 1 


196.0 


223.7 


235.5 


285 


J 86 


254.0 


130.3 


1 344 


133 2 


127. 1 


186 9 


191. « 


196 7 


224.5 


236.3 


286 


287 


2549 


130.8 


134.9 


133 7 


127.6 


187.5 


192. s 


197.4 


225.3 


237-1 


287 


288 


255-8 


131. 3 


135.4 


134-3 


128. 1 


188.2 


193 2 


198 I 


226.1 


238.0 


288 


389 


256.7 


131.8 


135-9 


134-8 


128.6 


1.88 9 


193-8 


198 8 


226.9 


238.8 


289 


290 


257.6 


132-3 


136.4 


135-3 


129.2 


189 S 


194-5 


199 5 


227.6 


239,6 


290 


291 


258.5 


132.7 


136.9 


135-8 


129.7 


190 2 


195-2 


20'0 2 


228.4 


240 5 


291 


292 


2594 


133.2 


137.4 


136-3 


130.2 


190.9 


195-9 


200 9 


229 2 


241 .3 


292 


293 


260.3 


133.7 


137.9 


136.8 


130.7 


191. 5 


196.6 


201 6 


230 


242. 1 


293 


294 


261 .2 


134-2 


138.4 


137-3 


131.2 


192 2 


197.3 


202 3 


230.8 


242.9 


294 


29s 


262.0 


134-7 


138 9 


137-8 


131.7 


192 9 


198.0 


203.0 


231 6 


243-8 


29s 


2?6 


262 .9 


135-2 


139 4 


138.3 


132 2 


193 6 


198.7 


203 7 


232.4 


244-6 


296 


297 


263.8 


135-7 


140.0 


138.8 


1^2.7 


194 i 


199.3 


204 4 


233 2 


245-4 


297 


298 


264.7 


136.2 


140.5 


139.4 


133 2 


194 9 


200.0 


20s I 


234 


246.3 


298 


299 


26s. 6 


136.7 


141 .0 


139-9 


133.7 


195 6 


200. 7 


20s 8 


234 8 


247. 1 


299 


300 


266.5 


137.2 


141 .5 


140.4 


1^4.2 


196 2 


201.4 


206.6 


235.5 


247-9 


300 


301 


267.4 


137.7 


142 .0 


140.9 


134 8 


196.9 


202 . I 


207 3 


236.3 


248.8 


301 


302 


268.3 


138.2 


142.5 


141. 4 


135 3 


197.6 


202.8 


208 


237 1 


249 6 


302 


303 


269.1 


138.7 


143 


141.9 


135.8 


198 3 


203. S 


208 7 


^37 9 


250.4 


303 


304 


270.0 


139-2 


143-s 


142.4 


136.3 


198 9 


204.2 


209 4 


238 7 


251-3 


304 


305 


270.9 


139.7 


144-0 


142.9 


136.8 


199.6 


204 9 


210. I 


239 5 


252.1 


30s 


306 


271.8 


140. 2 


144.5 


143-4 


137 3 


200 3 


20s 5 


210 8 


240.3 


252 9 


306 


307 


272.7 


140.7 


145.0 


144 


137.8 


201 


206. 2 


211 S 


241 I 


253 8 


307 


308 


273.6 


141. 2 


145-5 


144-5 


138.3 


201 6 


206.9 


212. 2 


241 9 


254 6 


308 


309 


274-5 


141-7 


146. 1 


1450 


138 8 


202 3 


207 6 


212.9 


242 7 


255-4 


309 


310 


275-4 


142.2 


146.6 


145-5 


139.4 


203.0 


208.3 


213 7 


243 5 


256.3 


310 


311 


276.3 


142.7 


147 I 


146.0 


139.9 


203 6 


209 


214 4 


244-2 


257 I 


311 


3«2 


.277-1 


143-2 


147.6 


146. 5 


140.4 


204.3 


209.7 


215 1 


245 


257-9 


312 


3'3 


278.0 


143-7 


148. 1 


147-0 


140.9 


205 


210.4 


215 8 


245-8 


258 8 


313 


3>4 


278.9 


144-2 


148 6 


147 6 


141.4 


205 7 


211 I 


216. S 


246 6 


259 6 


J14 


31S 


279.8 


144.7 


149 I 


148. 1 


141 .9 


206.3 


211. 8 


217 2 


247-4 


260 4 


31s 


316 


280.7 


145 2 


149 6 


I48.6 


142 .4 


207 


212. S 


217 9 


248.2 


261, 2 


316 


317 


281.6 


145.7 


150.1 


149.1 


143 


207 7 


213 I 


218 6 


249 


262 I 


317 


318 


282. s 


146 2 


150.7 


149 6 


143 5 


308 4 


213.8 


219 3 


249 8 


262.9 


318 


319 


283 4 


146,7 


151.2 


150.1 


144.0 


209 


214 S 


220 


250 6 


263.7 


319 


350 


284.2 


147.2 


151. 7 


150.7 


144.5 


209.7 


2IS.2 


220.7 


251 3 


264 6 


320 


321 


285 I 


147.7 


152 2 


151.2 


145.0 


210 4 


215.9 


221.4 


252 I 


265 4 


321 


322 


286 


J48.2 


152,7 


151. 7 


145.5 


aii.o 


2X6.6 


222.2 


252:9 


266 2 


322 


323 


285.9 


148.7 


153.2 


152.2 


146.0 


211. 7 


217-3 


222 9 


253 7 


267 1 


323 


324 


287 8 


149-2 


IS3-7 


152 7 


146.6 


212.4 


218 


223 6 


254-5 


267 9 


324 


32s 


288 7 


149.7 


154-3 


153 2 


147.1 


213. 1 


218.7 


224 3 


255 3 


26?. 7 


32s 


326 


289.6 


150.2 


154-8 


153. « 


147.6 


213.7 


219 4 


225 


256 I 


269 6 


326 


3^1 


290.5 


150.7 


155 3 


154.3 


148. I 


214.4 


220 I 


225 7 


256.9 


270 4 


327 


328 


291 4 


151.2 


155-8 


154 8 


148.6 


21S.1 


220. 7 


226 4 


257 7 


271.-2 


328 


329 


292.2 


151-7 


156.3 


155-3 


149. 1 


31S.8 


221.4 


227 I 


258.5 


272.1 


329 


330 


293 I 


152.2 


156.8 


1^5 8 


149.7 


216 4 


222. 1 


227.8 


259. 3 


272.9 


330 


331 


294.0 


152.7 


157.3 


156.4 


150. 2 


217. 1 


222 8 


228 5 


260 


273.7 


331 


332 


294.9 


153.2 


157-9 


156.9 


150.7 


217.8 


223 S 


229 2 


260 8 


274.6 


332 


333 


295.8 


153.7 


158 4 


157-4 


151.2 


218.4 


224. 2 


230 


261 6 


275.4 


333 


334 


296.7 


154. 2 


158 9 


157.9 


151.7 


219. 1 


224.9 


230 7 


262 4 


276.2 


334 


335 


297.6 


154.7 


159-4 


158.4 


152.3 


219.8 


225.6 


231.4 


263 2 


277.0 


33S 


336 


298. s 


155.2 


159-9 


159.0 


152.8 


220.5 


226.3 


2 2.1 


264.0 


277.9 


336 


337 


299.3 


155 8 


160. s 


159. 5 


1 53 . 3 


221 I 


227. 


232 8 


264.8 


278 7 


337 


338 


300. 2 


156 3 


161 .0 


160 


153. 8 


221.8 


227.7 


233 S 


265.6 


279 5 


338 


339 


301 I 


156 8 


161 .5 


160. s 


154.3 


222. s 


228.3 


234.2 


266.4 


280.4 


•339 



TABLES 



2ig 



MUNSON AND WALKER'S TABLE FOR CALCULATING SUGARS FROM 

CUPROUS OXIDE— (Continued) 

(Weights est Milligrams) 



342 

343 
344 

34S 

346 
347 
348 
349 

350 
351 
353 
353 
354 

355 
356 
357 
3S8 
359 

360 
361 
36a 
363 
364 

36s 
366 
367 
368 
369 

370 
371 
37a 
373 
374 

375 
375 
377 
378 
379 

380 
381 
38» 

383 



38s 
386 
387 
388 
389 

390 
391 
39» 
393 
394 



3oi.o 
3039 
303-8 
304-7 
305-6 

306. 5 
307-3 
308.1 
309.1 
310.0 

310.9 
3II-8 
312-7 
313-6 
314-4 

315-3 
316-2 
317-I 
318.0 
318.9 

319-8 
320.7 
321.6 
322.4 
3233 

3242 
325-1 
326.0 
326.9 
327.8 

328.7 
3295 
330.4 
3313 
332-2 

333-1 
3340 
334-9 
335-8 
336.7 

337-5 
338.4 
339-3 
340.2 
34I-I 

342.0 
342.9 
343-8 
344-6 
345-5 

346.4 
347.3 
348.2 
349." 
350.0 



57-3 
57-8 
58.3 
58.8 
59-3 

59.8 
60.3 
60.8 
61 .4 
61 .9 

62.4 
62 .9 
63.-4 
63 -9 
64.4 

64.9 
65.4 
66.0 
66. S 
67.0 

67. 5 
68.0 
68. S 
69.0 
69.6 



73-7 
74.2 
74.7 



76.3 
76.8 
77-3 

77-9 
78.4 
78.9 
79-4 
80.0 

80. S 
81..0 
81. S 
82.0 
82.6 

83.1 
83.6 
84.1 
84.7 
85.2 



Invert Sugar 
and Sucrose. 



Lactose. 



6j .0 
62.5 
63.1 
63.6 
64-. t- 

64.6 
65.1 
65-7 
66.2 
66.7 

67.2 
67.7 
68.3 
68.8 
69.3 

69.8 



71-4 
71.9 



74.0 

75-1 
75.6 
76.1 
76.7 
77-2 

77-7 
78.3 
78.8 
79-3 
79.8 

80.4 
80.9 
B1.4 
82.0 
82. 5 

83.0 
83.6 
84.1 
84.6 
85.2 

85.7 
86.2 
86.8 
87.3 
87.8 



88.9 



61 .0 
61.6 
62.1 
62.6 
63.1 

63-7 
64.2 
64.7 
65.2 
65-7 

66.3 
66.8 
67-3 
67.8 
68.4 

68.9 
69.4 
70.0 
70. S 
71.0 

71-5 
72.1 

72 .6 
73.1 
73.7 

74.2 
74.7 
75-2 
75-8 
76.3 

76.8 



78.4 



81.6 

82.1 
82.7 
83.2 
83.8 
84.3 

84.8 
85.4 
85-9 
86.4 
87.0 

87. 5 



89-7 



6 rt 



54.8 
55-4 
55-9 
56.4 
56.9 

■57'- 5 
58.0 
58.5 
59-0 
59-5 

60. 1 
60.6 
61. 1 
61:6 
62.3 

62 .7 
63.2 
63-7 
64-3 
64.8 

65.3 
65.8 
66.4 
06. 9 
67.4 

67.9 
68.5 
69.0 
69. s 
70.0 

70.6 
71. 1 



74-8 
75-3 

75-9 
76.4 
76.9 
77. 5 
78.0. 

78.5 
79-' 
79-6 
80.1 
80.6 

81.2 
81.7 
82.3 
82.8 
83-3 



O 



223-2 
223.8 
224-5 
22s. 2 
225-9 

226. 5 
227.2 
227.9 

228. S 
229.2 

229.9 
230.6 
23I-2 
231.9 
232.6 

233-3 
233-9 
234-6 
235- 3 
236.0 

236.7 
237.3 
238.0 
238.7 
239.4 

240.0 
240.7 
24I-4 
242. I 
242.7 

243.4 
244.1 

244.8 
245.4 

246. 1 

246.8 
247.5 

248. I 
248.8 

249. S 

250. 2 
250.8 
351.5 
252.2 
252.9 

253.6 
254-2 
254-9 
255-6 
256.3 

256.9 
2Sf7.6 
258.3 
259.0 
2S9.6 



229.0 
229.7 
230.4 
231. 1 
231.8 

232. 5 
233.2 
233.9 
234.6 
235.3 

235.9 
236. 6 
2-37 . 3 
238.0 
238.7 

239.4 
240. I 
240.8 
241 -5 
242.2 

242.9 
243.6 
244-3 
245 -o 

245.7 

246.4 
247.0 
247.7 
248.4 
249.1 

249.8 
250.5 
251.2 
251.9 
252.6 

253.3 

254-0 
254-7 
255-4 
256. I 

256.8 
257-5 
258. I 
258.8 
259.5 

260.2 
260.9 

261 . 6 
262.3 
263.0 

263.7 
264.4 
265. 1 
265.8 
366. S 



234-9 
235.6 
236.3 
237. (^ 
237-8 

238. S 
239.2 
239.9 
240.6 
241.3 

242.0 
242.7 
243.4 

244.1 
244.8 

245.6 
246.3 
247.0 
247.7 
248.4 

249.1 
249.8 
2505 
251.2 
252.0 

252.7 
253.4 
254-1 
254-8 
255-5 

256.2 
256.9 
257-7 
258.4 
259.1 

259 8 
260. 5 
261.2 
261.9 
262.6 

263.4 
264.1 
264.8 
265. S 
266.2 

266.9 
367.6 
268.3 
269.0 
269.8 

370. s 

371.3 
271.9 
273.6 

273.3 



o 



267. 1 
367.9 
368.7 
C69.S 
270.3 

271. 1 
271.9 
272.7 
273-5 
274.3 

37S-0 
375-8 
276.6 
277.4 
278.2 

279.0 
279-8 
280.6 
281.4 
283.2 

282.9 
283.7 
284. 5 
385.3 



386.9 
287.7 



390.0 

290.8 
391 .6 

2^2.4 

293.2 
394-0 

294-8 

295-6 
296.4 
397-2 
297.9 

298.7 
299-5 
300.3 
301 . 1 
301.9 

303.7 
303-5 
304-2 
3050 
305-8 

306.6 
307-4 
308.3 
309.0 
309-8 



281. 

2*2. 
283. 
283. 



285.4 
286.2 
287.0 
287.9 
288.7 

389.5 
290.4 
291 .3 

293 .0 

292.8 

293-7 
394-S 
395-3 
296. 2 
297-0 

297.8 
298.7 
399-5 

ioo-3 

301 .3 

303.0 
303.8 
303-6 
304-5 
305-3 

306.1 
3070 
307-8 
308.6 
309-5 

310.3 

3II-I 
312.0 
313.8 
313-6 

314-5 
315 3 
316.1 
316.9 
317-8 

318.6 
319-4 
320.3 
321. 1 
321.9 

322.8 
3236 
324.4 
325.3 
326.1 



340 
341 
343 
343 
344 

345 
346 
347 
348 
349 

350 
351 
35* 
353 
354 

35S 
356 
357 
358 
359 

360 
361 
363 
36J 
364 

36S 
366 

36* 
369 

370 
371 
37» 
373 
374 

"I 
370 

378 
379 

380 
381 
381 
383 
384 

38s 
386 
387 
388 
389 

390 

39« 
391 
393 
394 



220 



APPENDIX 



MUNSON AND WALKER'S TABLE FOR CALCULATING SUGARS FROM 

CUPROUS OXIBE— (Continued) 

(Weights in Milligrams) 



Q 








Invert Sugar 
and Sucrose. 


Lactose. 


Maltose. 


q 


3 
















3 


o 







































d 








^^ 


V 








a 


^rt 




j2 

+ 













'S 
O 


"5 





1 


^ 


& 
^ 




+ 




+ 


1 






tn 


w 


Su 


W iT 


3 


a 


a 


a 


2 




3 


u 


Q 


1 


gs 


B S 

















3 


o. 

3 


0. 







2§" 


1 


n 

K 
a 


n 

a 

a 


n 


a 


3 


O 





Q 




d 


« 


C 





u 








CJ 


395 


350. 9 


185.7 


191 .0 


190.2 


183-9 


26a. 3. 


267.2 


274-0 


310.6 


336.9 


395 


396 


351. 8 


186.2 


191 .6 


190.7 


184.4 


261.0 


267.9 


274.7 


311.4 


327.7 


396 


397 


352.6 


186.8 


192.x 


191.3 


184.9 


261.7 


268.6 


275.5 


312. 1 


328.6 


397 


398 


353-5 


187.3 


192.7 


191.8 


185. s 


262.3 


269.3 


276.2 


312.9 


3294 


398 


399 


354.4 


187.8 


193-3 


192.3 


186-0 


263.0 


269.9 


276.9 


313.7 


330.2 


399 


400 


335-3 


188.4 


193-7 


192.9 


186. s 


263.7 


270.6 


277.6 


314-5 


331-1 


460 


401 


356.2 


188.9 


194.3 
194.8 


193-4 


187.1- 


264.4 


271-3 


278.3 


315-3 


331-9 


401 


40J 


357-1 


189.4 


194.0 


187.6 


265.0 


272. 


279.0 


316-1 


332.7 


402 


403 


358.0 


189.9 


195-4 


194-5 


188.1 


265.7 


272.7 


279.7 
280.4 


3i*-9 


333.6 


403 


404 


358.9 


190.5 


195-9 


19S-0 


188.7 


266.4 


273.4 


317-7 


334-4 


404 


40s 


359.7 


191. 


196-4 


195-6 


189.2 


267.1 


274.1 


281. I 


3x8.5 


335-2 


40s 


406 


360.6 


191. 5 


197-P 


196.1 


189-8 


267.8 


274.8 


281.9 


319-2 


336.0 


406 


407 


361. S 


192 . 1 


197-5 


196.7 


190.3 


268.4 


275.5 


282.6 


320.0 


336.9 


407 


408 


362.4 


192.6 


198.1 


197-3 


190.8 


269. 1 


276.2 


283.3 


320.8 


337-7 


40S 


409 


363.3 


193. 1 


198.6 


197-7 


191.4 


269.8 


276.9 


284.0 


321. 6 


338.5 


409 


410 


364.2 


193.7 


199. 1 


198.3 


191.9 


270. s 


277.6 


284.7 


322.4 


339.4 


410 


411 


365-1 


194.2 


199.7 


198.8 


193. s 


271.2 


278.3 


285.4 


323-2 


340.2 


411 


412 


366.0 


194.7 


200.2 


199.4 


193.0 


271.8 


279,0 


286.2 


324.0 


341.0 


413 


413 


366.9 


195-2 


200.8 


199.9 


193-5 


272. s 


279.7 


286.9 


3248 


341.9 


413 


414 


367.7 


I9S.& 


201.3 


aoo.s 


I94-I 


273-2 


280.4 


287.6 


325-6 


343.7 


414 


415 


368.6 


196.3 


30I.8 


30I.0 


194-6 


273.0 


281.1 


288.3 


326.3 


343-5 


41S 


416 


369-5 


196.8 


302.4 


201 .6 


195-3 


274-6 


281.8 


289.0 


337-x 


344-4 


416. 


417 


370.4 


197.4 


303 .9 


202 . 1 


195-7 


275-2 


282.5 


289.7 


327-9 


345-2 


417 


418 


371.3 


197.9 


303.5 


202.6 


196.2 


275-9 


283.2 


290.4 


328.7 


346.0 


418 


419 


372-3 


198.4 


204.0 


203.3 


196.8 


276.6 


283.9 


291-2 


329-5 


346.8 


419 


4JO 


373-1 


199.0 


204.6 


303.7 


197.3 


277-3 


284.6 


291.9 


330.3 


347.7 


420 


421 


374-0 


199-5 


205. 1 


204.3 


197.9 


277.9 


285.3 


292.6 


331-1 


348. 5 


421 


422 


374-8 


aoo. I 


205.7 


204.8 


198.4 


278.6 


286.0 


293.3 


331.9 


349-3 


422 


423 


375-7 


200.6 


206.2 


205.4 


198.9 


279.3 


286.7 


294.0 


332-7 


350-2 


423 


424 


376.6 


201. 1 


306.7 


205.9 


199.5 


280.0 


287.4 


294.7 


333-4 


351.0 


424 


42s 


377-5 


201 .7 


207.3 


206.5 


200.0 


280.7 


288.1 


29S.4 


334-2 


351.8 


425 


426 


378.4 


202 .2 


207.8 


207.0 


200.6 


281 3 


288.8 


296.2 


335.0 


352.7 


426 


427 


379-3 


202.8 


208.4 


207.6 


201 . 1 


282.0 


289,4 


296.9 


335.8 


353-5 


427 


428 


380.2 


203.3 


208.9 


208.1 


201.7 


282.7 


290. 1 


297.6 


336.6 


354.3 


438 


429 


381. 1 


203.8 


309. S 


208.7 


202 .3 


283.4 


290.8 


298.3 


337.4 


355.1 


439 


430 


382.0 


204.4 


210.0 


209.2 


202.7 


284.1 


291. S 


299.0 


338.2 


356.0 


430 


431 


382.8 


204.9 


210.6 


209,8 


203.3 


284.7 


292. 2 


299-7 


3390 


356.8 


43X 


432 


383.7 


205.5 


211 . I 


210.3 


203.8 


285.4 


292.9 


300. s 


339-7 


357-6 


433 


433 


384.6 


206.0 


211. 7 


210.9 


204.4 


286.1 


293.6 


301.2 


340. 5 


358. 5 


433 


434 


385.5 


206. S 


213.2 


211.4 


204.9 


286.8 


294.3 


301.9 


341-3 


359-3 


434 


43 S 


386.4 


207. t 


212.8 


2ii .0 


205. 5 


287.5 


295.0 


302^.6 


343.1 


360. 1 


436 


436 


387.3 


207.6 


213-3 


313. 5 


206.0 


288.1 


295.7 


303.3 


343.9 


361.0 


••^z 


388.2 


208.2 


313-9 


313. I 


206.6 


288.8 


296.4 


304.0 


343.7 


361.8 


^^l 


438 


389-1 


208.7 


214-4 


313-6 


207.1 


289. s 


297- I 


304.7 


344. 5 


362.6 


438 


439 


390.0 


209.3 


215.0 


214.3 


i07.7 


290.2 


297.8 


30s. S 


345.3 


363-4 


439 


440 


390.8 


209 8 


•215.5 


314.7 


208. 3 


290.9 


298.5 


306.2 


346.x 


364-3 


440 


441 


391.7 


310.3 


216. 1 


315-3 


208.8 


291. S 


299. 2 


306.9 


346-8 


365-1 


441 


442 


392.6 


210.9 


216.6 


315-8 


209-3 


192.3 


299.9 


367.6 


347.6 


365-9 


443 


443 


393 -S 


211 .4 


217.3 


216.4 


209.9 


292.9 


300.6 


308.3 


348.4 


366.8 


443 


444 


394-4 


212. 


217.8 


216.9 


210.4 


293.6 


301.3 


309.0 


349-3 


567-6 


444 


44S 


395-3 


212. S 


218.3 


217-5 


211 .0 


294-2 


302.0 


309.7 


3SO.O 


368.4 


445 


446 


396.2 


313. I 


218.9 


218.0 


211. s 


204 9 


302.7 


310.5 


350.8 


369 3 


446 


447 


397-1 


213-6 


219.4 


218.6 


212 . 1 


29S-6 


303-4 


311. B 


351. 6 


370.1 


447 


448 


397-9 


214 I 


220.0 


219. 1 


212.6 


296.3 


304.1 


3IJ.9 


352.4 


370.9 


448 


449 


398.8 


214.7 


220.$ 


319.7 


313-.3 


297-0 


304.8 


3X2.6 


353 -3 


371-7 


44» 



TABLES 



221 



MUNSON AND WALKER'S TABLE FOR CALCULATING SUGARS FROM 
CUPROUS OXIDE— (Cotitimied) 

(Weights in Milligrams) 



q 








Invert Sugar 
and Sucrose. 


Lactose. 


Maltose. 





3 
















3 


y 








_ 






d 











■8 
■a 
o 


1 




i 


2 


3 




a. 


0" 

,+ 




d 

+ 


V 

•0 

■a 





it 


si 



t. 

> 




a^ 





§ 


S 


6 


d 


s 


a 

3 


0. 










s 


a 


■ a 


X 
a 


1 

a 


o 





Q 




6 


" 




















450 


399-7 


215.2 


221 . I 


220.2 


313.7 


297.6 


30s. s 


313.3 


353. 9 


372.6 


45a 


451 


400.6 


215-8 


221.6 


220.8 


214.3 


298.3 


306.2 


314.0 


354.7 


373.^ 


451 


45» 


401. 5 


216.3 


333. 2 


321 -i 


214..8 


299.0 


306.9 


314.7 


355. 5 


374.3 


452 


453 


402.4 


316.9 


222.-8 


221 .9 


215.4 


299.7 


307.6 


315.5 


356.3 


375.1 


453 


4S4 


403 -3 


217.4 


333.3 


223. S 


215.9 


300.4 


308.3 


3l6.2 


3S7-I 


375.9 


454 


455 


404.3 


218.0 


233.9 


223.0 


216. s 


301. J 


309.0 


316.9 


357-9 


376.7 


45S 


456 


405.1 


218. s 


324.4 


223.6 


217.0 


301.7 


309.7 


317.6 


358.7 


377.6 


456 


457 


405.9 


219. 1 


225.0 


324.1 


217.6 


302.4 


310.4 


318.3 


359. 5 


378.4 


457 


458 


406.8 


219.6 


225^5 


334.7 


318. 1 


303.1 


311. 1 


319.0 


360.3 


379.2 


458 


459 


407.7 


220.3 


226.1 


335.3. 


218.7 


303.8 


311. 8 


319.8 


361 ,0 


380.0 


459 


460 


408.6 


220.7 


226.7 


225.8 


219.2 


304. s 


312. S 


320. s 


361,8 


380.9 


460 


461 


409.5 


221.3 


227.2 


226.4 


219.8 


30s -I 


3Ii^2 


321.2 


362.6 


381.7 


461 


46a 


410.4 


221.8 


227.8 


336.9 


'!20.3 


30s -8 


313.9 


321.9 


363.4 


382.5 


462 


463 


411 -3 


222.4 


228.3 


227.5 


220 9 . 


306. 5 


314-6 


322.6 


364.2 


383.4 


463 


464 


412.2 


323 .9 


328 9 


328.1 


221.4 


307.2 


31S.3 


323.4 


365.0 


384.2 


464 


46s 


4130 


223. 5 


339. 5 


228.6 


222.0 


307.9 


316.0 


324.1 


365.8 


385.0 


46s 


466 


413-9 


224,0 


030:0 


329.3 


222.5 


308.6 


316.7 


324.8 


366.6 


385.9 


466 


467 


414-8 


224.6 ' 


330.6 


339.7 


223.1 


309.2 


317.4 


32s- s 


367.3 


386.7 


467 


468 


4IS-7 


225 -t 


231.2 


230.3 


223:7 


309.9 


318. 1 


326.2 


368.1 


387-s 


468 


469, 


416.6 


335.7 


?3I.7 


230.9 


224.2 


310.6 


318.8 


326.9 


368.9 


388.3 


469 


470 


417. s 


226. 2 


232.3 


231.4 


434.8 


311. 3 


319, S 


327.7 


369.7 


389-2 


470 


471 


418.4 


226.8 


232.8 


232.0 


225-3 


312.0 


320.2 


328.4 


370.5 


390.0 


471 


472 


419-3 


227.4 


233.4 


232.5 


225-9 


312.6 


320.9 


329.1 


371.3 


390.8 


472 


473 


420.2 


227-9 


234.0 


233-1 


226.4 


313-3 


321 .6 


329.8 


372.1 


391.7 


473 


474 


421 .0 


228 5 


234. S 


233.7 


227.0 


314.0 


322.3 


330. s 


372,9 


392. s 


474 


475 


42 r . 9 


229 


;23S.i 


234.2 


227.6 


314.7 


323.0 


331.3 


373.7 


393-3 


A^i 


476 


422.8 


229.6 


235.7 


234.8 


228.1 


31S.4 


323.7 


332,0 


374.4 


394-2 


476 


477 


423.7 


230.1 


236.2 


235. 4 


,228.7 


316. t 


324.4 


332.7 


375.2 


39S-0 


477 


478 


424.6. 


230.7 


236.8 ' 


235-9 


229.3 


316.7 


32s. I 


333.4 


376.0 


395-8 


478 


479 


425 5 


231.3 


237-4 


236. 5 


229.8 


317.4 


325,8 


334.1 


376.8 


396.6 


479 


480 


426.4 


T23I.8 


237.9 


237-1 


230.3 


318. 1 


326. S 


334.8 


377.6 


397.5 


480 


481 


427-3 


232.4 


338.5 


237-6 


230.9 


318.8 


327.2 


335.6 ■ 


378.4 


398.3 


481 


483 


428.1 


232 9 


239.1 


238.2 


231. S 


319 -S 


327:9 


336.3 


3 79-2 


399- > 


483 


483 


429.0 


233.5 


239.6 


238.8 


232.0 


320.1 


328.6 


337,0 


380.0 


400.0 


483 


484 


429 9 


234 I 


240.3 


239.3 


232.6 


320.8 


329.3 


337.7 


380.7 


400.8 


484 


48s 


430.8 


234.6 


240.8 


339.9 


233.2 


321. s 


330.0 


338.4 


381. S 


401 .6 


*li 


486 


431 7 


235.2 


241.4 


240.5 


2337 


322.2 


30.7 


Zi9.l 


382.3 


402.4 


486 


487 


433.6 


235.7 


241.9 


241 .0 


234.3 


322.9 


331.4 


339.9 


383 . 1 


403.3 


*ll 


488 


433. 5 


266.3 


242.5 


241 .6 


234.8 


323-6 


332.1 


340.6 


385.9 


404.1 


488 


489 


434-4 


236.9 


243. « 


243.2 


?35.4 


324.2 


332,8 


341-3 


384.7 


404 -9 


489 


490 


435 -3 




237-4 


243.6 


242-7 


236.0 


324 9 


333. S 


342.0 


385.5 


405.8 


490 



222 



APPENDIX 



EQUIVALENTS OF INDICES OF REFRACTION AND BUTYRO-REFRAC- 
TOMETER READINGS 



Refrac- 








Fourth Decimal o« tin 








tive 














- 








Index. 






















"Z5. 





1 


2 


3 


4 


5 


6 


7 


8 


9 










SCALE READINGS 










1.422 


0.0 


0.1 


0.2 


0.4 


0-5 


0.6 


0.7 


0.9 


I.O 


I.I 


1.423 


1.2 


1-4 


1-5 


1.6 


1-7 


1-9 


2.0 


2.1 


2.2 


2.4 


1.424 


2.5 


2.6 


2.7 


2.8 


3-0 


3-1 


3-2 


3-3 


3-5 


3-6 


1.425 


3-7 


3-8 


4-0 


4.1 


4-2 


4-3 


4-5 


4-6 


4-7 


4.8 


1.426 


5-0 


S-i 


5-2 


5-4 


S-S 


S-6 


5-7 


5-9 


6.0 


6.1 


1.427 


6.2 


6.4 


6-5 


6.6 


6.8 


6.9 


7.0 


7-1 


7-2 


7-4 


1.428 


7-5 


7-6 


■7-7 


7-9 


8.0 


8.1 


8.2 


8.4 


8-5 


8.6 


1.429 


8,7 


8.9 


9.0 


9.1 


9-2' 


9-4 


9-5 


9.6 


9.8 


9-9 


1.430 


10. 


10. 1 


10-3 


10.4 


lo.s 


10.6 


10.7 


10.9 


n.o 


11.J 


I-43I 


11-3 


II. 4 


"■5 


,11.6 


II. 8 


1 1.9 


12.0 


12.2 


12-3 


12.4 


1.432 


12.5 


12.7 


12.8 


12.9 


13-0 


13-2 


13-3 


^3-5 


13.6 


13.7 


1-433 


13-8 


14.0 


14. 1 


14.2 


14.4 


14-5 


14.6 


14-7 


14-9 


15.0 


1-434 


.15.1 


15-3 


15-4 


15-5 


15-6 


15-8 


15-9 


16.0 


16.2 


16.3 


1-435 


x6.4 


16.6 


16.7 


16.8 


17.0 


17-1 


17.2 


17-4 


17-5 


17.6 


1.436 


17.8 


17.9 


18.0 


18.2 


18.3 


18.4 


18.5. 


18.7 


18.8 


18.9 


1-437 


19. 1 


19.2 


19-3 


19-S 


19.6 


19-7 


19.8 


20.0 


20.1 


20.3 


1.438 


?o.4 


20.5 


20.6 


20.8 


20.9 


21. 1 


21.2 


21.3 


21.4 


21.6 


1-439 


21.7 


21.8 


22.0 


22.1 


22.2 


22.4 


22.5 


22.6 


■ 22.7 


22.9 


1.440 


23.0 


23.2 


23-3 


23-4 


23-5 


23-7 


23.8 


23-9 


24.1 


24.2 


1. 441 


24-3 


24-5 


24.6 


24-7 


24.8 


2t;.o 


25-1 


25-2 


25-4 


25.5 


1.442 


25.6 


25-8 


25-9 


26.1 


26.2 


26.3 


26.S 


26.6 


26.7 


26.9 


1-443 


27.0 


27.1 


27-3 


27-4 


27-5 


27-7 


27.8 


27-9 


28.1 


28.2 


1.444 


28.3 


28.S 


28.6 


28.7 


28.9 


29.0 


29.2 


29-3 


29-4 


29.6 


1-445 


29.7 


29.9 


30.0 


30.1 


30-3 


30-4 


30.6 


30-7 


30.8 


30.9 


1.446 


31 -i 


31.2 


31-4 


31-5 


31.6 


31-8 


31-9 


32-1 


32.2 


32-3 


1.447 


32-5 


32.6 


32.8 


32-9 


33-0 


33-2 


33-3 


33-5 


33-6 


33.7 


1.448 


33 -J9 


34-0 


34-2 


34-3 


34-4 


34.6 


34-7 


34-9 


3S-0 


35.1 


1.449 


35-3 


35-4 


35-6 


35-7 


35-8 


36.0 


36.1 


36.3 


36.4 


36.5 


1.450 


36-7 


36.8 


37-0 


37-1 


37-2 


37-4 


37-5- 


37-7 


37-8 


37-9 


1.451 


38.1 


38-2 


38-3 


38.S 


38-6 


38.7 


38-9 


39-0 


39-2 


'39- 3r 


1.452 


39.-5 


39-6 


39-7 


39-9 


40.0 


40.1 


40.3 


40.4 


40.6 


40.7 


1-453 


40.9 


41.0 


41. 1 


41-3 


41.4 


41-5 


41.7 


41.8 


42.0 


42.1 


1.454 


42.3 


42.4 


42.5 


42.7 


42.8 


43-0 


^^■1 


43-3 


■ 43-4 


43-6 


I -455 


43-7 


43-9 


44.0 


44-2 


44-3 


44-4 


44.6 


44-7 


44-9 


45.0 


1.456 


45-2 


45-3 


45-5 


45-6 


45-7 


45-9 


46.0 


46.2 


46.3 


46.4 


1.457 


46.6 


46.7 


46.9 


47-0 


47-2 


47-3 


47-5 


47-6 


47-7 


47-9 


1.458 


48.0 


48.2 


48.3 


48.5 


48.6 


48.8 


48-9 


49-1 


49-2 


49 4 


1. 459 


.49-5 


49-7 


49.8 


50.0 


SO. I 


50.2 


50.4 


50.5 


50-7 


50.8 


1.460 


51.0 


51.1 


51-3 


51-4 


51.6 


51-7 


51-9 


52-0 


52.2 


52-3 


1.461 


52-S 


52.7 


52-8 


53-0 


53-1 


53-3 


53-4 


53-6 


53-7 


53-9 


1.402 


S4-0 


54.2 


54-3 


54-5 


54-6 


54.8 


55-0 


55-1 


55-3 


55.4 


1.463 


55-6 


55-7 


55-9 


56.0 


56.2 


56-3 


56-5 


56.6 


56.8 


56.9 


1.464 


57-1 


57-3 


57-4 


■ 57-6 


57-7 


57-9 


58.0 


58-2 


58.3 


58.5 


i.465 


58.6 


58.8 


58-9 


59-1 


59-2 


59-4 


59-5 


59-7 


59-8 


60.0 


1.466 


60.2 


60.3 


60.5 


60.6 


60.8 


60.9 


61. 1 


61.2 


61.4 


61.5 


1,467 


61.7 


61.8 


62.0 


62.2 


62.3 


- 62.5 


62.6 


62.8 


62.9 


63.1 


1.468 


63.2 


63-4 


63 S 


63-7 


63.8 


64.0 


64.2 


64-3 


64-5 


64.7 


1.469 


64.8 


65.0 


65.1 


65-3 


65.4 


65.6 


65-7 


65-9 


66.1 


66.3 



TABLES 



223 



EQUIVALENTS OF INDICES OF REFRACTION AND BUTYRO-REFRAC- 
TOMETER READINGS— {ConUnued) 



Refrac- 








Fourth Decimal of n^_ 








tive 






















Index. 






















*>D. 





1 


2 


3 


4 


5 


6 


7 


8 


9 










SCALE READINGS 










1.470 


66.4 


66-5 


66.7 


66.8 


67.0 


67.2 


67-3 


67-5 


67.7 


67.8 


1. 471 


68.0 


68.1 


68.3 


68.4 


68.6 


68.7 


68,9 


69.1 


69.2 


69.4 


1.472 


69-5 


69.7 


69.9 


70.0 


70.2 


70-3 


70.5 


70.7 


70.8 


71.0 


1-473 


71. 1 


71-3 


71-4 


71.6 


71-8 


71.9 


72 


I 


72.2 


72.4 


72.5 


1.474 


72.7 


72.9 


73-0 


73-2 


73-3 


73-5 


73 


7 


73-8 


74.0 


74-1 


I.47S 


74-3 


74-5 


74.6 


74-8 


7.S-0 


7S-I 


75 


i 


75-5 


75-6 


75-8 


1.476 


76.0 


76.1 


76.3 


76-S 


76.7 


76.8 


77 





77-2 


77-3 


77-S 


1-477 


77-7 


77-9 


78.1 


78.2 


78.4 


78.6 


78 


7 


78.9 


79.1 


79.2 


1.478 


79-4 


79-6 


79-8 


80.0 


80. 1 


80.3 


80 


5 


80.6 


80.8 


81.0 


1.479 


81.2 


81.3 


81.5 


81.7 


81.9 


82.0 


82 


2 


82.4 


82.5 


82.7 


1.480 


82.9 


83.1 


83-2 


83-4 


83.6 


83.8 


83 


9 


84.1 


84-3 


84-5 


1. 481 


84.6 


84.8 


85.0 


85.2 


85-3 


85-5 


85 


7 


85-9 


86.0 


86.2 


1.482 


86.4 


86.6 


86.7 


86.9 


87.1 


87-3 


87 


5 


87.6 


87.8 


88.0 


1.483 


88.2 


88.3 


88-5 


88.7 


88.9 


89.1 


89 


2 


89-4 


89.6 


89.8 


1.484 


90.0 


90.2 


9°-3 


90-5 


90.7 


90.9 


91 


I 


91.2 


91.4 


91.6 


1,48s 


91.8 


92.0 


92.1 


92-3 


92-5 


92.7 


92 


9 


93-0 


93-2 


93-4 


1.486 


93-6 


93-8 


94.0 


94-1 


94-3 


94-5 


94 


7 


94-8 


95-0 


95-2 


1-487 


95-4 


9S-6 


95-8 


96.0 


96.1 


96-3 


96 


6 


96.7 


96.9 


97.0 


1.488 


97-2 


97-4 


97-6 


97.8 


98.0 


98.1 


98 


3 


98.5 


98.7 


98-9 


1.489 


99.1 


99.3 


99.4 


99.6 


99.8 


lOO.Q 











224 



APPENDIX 



GEERLIG'S TABLE FOR CALCULATING DRY SUBSTANCE OF SAC- 
CHARINE PRODUCTS FROM REFRACTIVE INDEX AT 28° C. 
Find in the table the refractive index which is next lower than the reading 
actually made. and note the corresponding whole number for the per cent of dry- 
substance. Subtract the refractive index obtained from the table from the observed 
reading; the decimal corresponding to this difference, as given in the column 
so marked, is added to the whole per cent of dry substance as first obtained. 





Per 






Per 




Refrac- 


Cent 


Decimals to be Added for 


Refrac- 


Cent 


Decimals to be Added for 


tive 


Dry 


Fractional Readings. 


tive 


Dry 


Fractional Readings. 


Index. 


Sub- 
stance. 




Index. 


Sub- 
stance. 




1-3335 


I 


0.0001=0.05 


0.0010=0.75 


1.4083 


45 


0.0004 = 0.2 


0.0015 = 0.75 


1-3349 


2 


0.0002 = 0.1 


0.0011 = 0.8 


1.4104 


46 


0.0005 = 0.25 


0.0016 = 0.8 


1-3364 


3 


0.0003 = 0.2 


0.0012 = 0.8 


I. 4124 


47 


0.0006 = 0.3 


0.0017 = 0.85 


1-3379 


4 


0.0004 = 0.25 


0.0013 = 0.85 


I. 4145 


48 


0.0007 = 0.35 


0.0018 = 0.9 


1-3394 


5 


0.0005 = 0.3 


0.0014 = 0.9 


I. 4166 


49 


0.0008 = 0.4 


0.0019=0.95 


1-3409 


6 


0.0006 = 0.4 


0.0015=1.0 


1.4186 


50 


0.0009 = 0.45 


0.0020=1.0 


1.3424 


7 


0.0007 = 0.5 




1.4207 


51 


0.0010 = 0.5 


0.002I = I.O 


1-3439 


8 


0.0008 = 0.6 




1.4228 


52 


0.0011 = 0.55 




1-3454 


9 


0.0009=0.7 




1.4219 


53 






1.3469 


10 






1.4270 


54 






1.3484 


11 


0.0001 = 0.05 




1.4292 


55 


0.0001 = 0.05 


0.0013 = 0.55 


1-3500 


12 


0.0002 = 0.1 




1-4314 


56 


0.0002 = 0.1 


0.0014=0.6 


1-3516 


13 


0.0003 = 0.2 




1-4337 


57 


0.0003 = 0.1 


0.0015 = 0.65 


1-3530 


14 


0.0004 = 0.25 




1-4359 


58 


0.0004 = 0.15 


0.0016 = 0.7 


1-3546 


IS 


0.0005 = 0.3 




1.4382 


59 


0.0005 = 0.2 


0.0017 = 0.75 


1-3562 


16 


0.0006 = 0.4 




I -4405 


60 


0.0006 = 0.25 


0.0018 = 0.8 


1-3578 


17 


0.0007 = 0.45 




1.4428 


61 


0.0007 = 0.3 


0.0019 = 0.85 


1-3594 


18 


0.0008 = 0.5 




1-4451 


62 


0.0008 = 0.35 


0.0020=0.9 


1.3611 


19 


0.0009 = 0.6 




1.4474 


63 


0.0009 = 0.4 


0.0021=0.9 


1.3627 


20 


0.0010 = 0.65 




1.4497 


64 


0.0010 = 0.45 


0.0022 = 0.95 


1.3644 


21 


0.0011 = 0.7 




1.4520 


65 


0.0011 = 0.5 


0.0023=1.0 


1.3661 


22 


0.0012 = 0.75 




1-4543 


66 


0.0012 = 0.5 


0.0024=1.0 


1.3678 


23 


0.0013 = 0.8 




1.4567 


67 






1-3695 


24 


0014 = 0.85 




I -4591 


68 






I. 3712 


25 


0.0015 = 0.9 


_ 


I. 4615 


6^ 






1-3729 


26 


0.0016 = 0.95 




1.4639 
1.4663 
1.4687 


70 

71 

72 
















1-3746 
1-3764 


27 
28 


0.0001 = 0.05 


0.0012 = 0.6 
0.0013 = 0.65 










0.0002 = 0.1 










1.3782 


29 


0.0003 = 0.15 


0.0014=0.7 


1.4711 


73 


0.0001 = 0.0 


0.0015=0.55 


1 . 3800 


30 


0.0004 = 0.2 


0.0015 = 0.75 


1-4736 


74 


0.0002 = 0.05 


0.0016 = 0.6 


1.3818 


31 


0.0005 = 0.25 


0.0016 = 0.8 


1.4761 


75 


0.0003 = 0.1 


0.0017 = 0.65 


1-3836 


32 


0.0006 = 0.3 


0.0017 = 0.85 


1.4786 


76 


0.0004 = 0.15 


0.0018 = 0.65 


1-3854 


33 


0.0007 = 0.35 


0.0018 = 0.9 


1.4811 


77 


0.0005 = 0.2 


0.0019=0.7 


1-3872 


34 


0.0008 = 0.45 


0.0019=0.95 


1.4836 


78 


0.0006 = 0.2 


0.0020=0.75 


1-3890 


35 


0.0009 = 0.4 


0.0020=1.0 


1.4862 


79 


0.0007 = 0.25 


0.0021=0.8 


1-3909 


36 


0.0010 = 0.5 


0.0021 = 1.0 


1.4888 


80 


0.0008 = 0.3 


0.0022 = 0.8 


1.3928 


37 


0.0011 = 0.55 




1.49x4 


81 


0.0009=0.35 


0.0023 = 0.851 


1-3947 


38 






1.4940 


82 


0.0010=0.35 


0.0024 = 0.9 


1-3966 


39 






1.4966 


83 


0.0011 = 0.4 


0.0025 = 0.9 


1-3984 


40 






1.4992 


84 


0.0012 = 0.45 


0.0026=0.95 


1-4003 


41 






1.5019 


85 


0.0013 = 0.5 


0.0027= 1.0 










I - 5046 


86 


0014 = 0.5 


0.0028=1.0 










1-5073 


87 
















1.4023 


42 


0.0001 = 0.05 


0.0012 = 0.6 


1.5100 


88 






1-4043 


43 


0.0002 = 0.1 


0.0013 = 0.65 


1.5127 


89 






1.4063 


44 


0.0003 = 0.15 


0.0014 = 0.7 


1.5155 


90 


• 





TABLES 



225 



TEMPERATURE CORRECTIONS FOR USE WITH GEERLIG'S TABLE, 

PAGE 224 



Tempera- 


Dry Substance. 


ture of the 
Prisms in 





5 


xo 


•5 


20 


25 1 30 1 40 ! 


so 


60 


70 


80 


90 


"C. 


Subtract — 


20 


0-53 


0.54 


55 


0.56 


0.57 


0.58 


0.60 


0.62 


0.64 


0.62 


0.61 


0.60 


0.58 


21 


.46 


• 47 


4« 


• 49 


•50 


•51 


.52 


• 54 


•Sb 


•54 


•S3 


•52 


•50 


22 


.40 


-41 


42 


• 42 


.43 


.44 


.45 


■47 


.48 


•47 


.40 


• 45 


• 44 


23 


.33 


•33 


34 


•35 


.3f 


•37 


•38 


•39 


.40 


•39 


.38 


•38 


•38 


24 


.26 


.26 


27 


.28 


.28 


.29 


•30 


•31 


•32 


•31 


•31 


•30 


-30 


"5 


.20 


.20 


21 


.21. 


.22 


.22 


•23 


.23 


• 24 


•23 


•23 


•23 


.22 


26 


.12 


.12 


13 


.14 


.14 


• 15 


• 15 


.16 


-lO 


.16 


• 15 


• 15 


• 14 


27 


.07 


.07 


07 


.07 


•07 


-07 


.08 


.08 


.08 


.08 


.08 


.08 


.07 




Add— 


29 


0.07 


D.07 


07 


0.07 


0.07 


0.07 


0.08 


0.08 


0.08 


0.08 


0.08 


0.08 


0.07 


30 


.12 


.12 


13 


• 14 


.14 


• 14 


•IS 


•15 


^16 


.16 


.16 


.15 


■14 


31 


■.20 


.20 


21 


.21 


.22 


.22 


•23 


•23 


• 24 


•23 


•23 


.23 


.22 


32 


.26 


.26 


27 


.28 


.28 


.29 


•30 


•31 


•32 


•31 


•31 


•30 


-30 


33 


•33 


•33 


34 


-35 


•30 


•37 


•38 


•39 


.40 


•39 


•3« 


-38 


.38 


34 


.40 


• 41 


42 


• 42 


•43 


• 44 


•45 


-47 


.48. 


•47 


.40 


-45 


-44 


35 


.46 


•47 


.48 


-49 


•50 


•51 


-52 


•54 


■50 


■ 54 


.53 


-52 


•50 



226 



APPENDIX 



HEHNER'S TABLE FOR CALCULATING ALCOHOL FROM SPECIFIC 

GRAVITY 





— 

Absolute Alcohol. 


Spec. 


Absolute Alcohol. 


Spec. 


Absolute Alcohol. 


Spec. 




















Grav. 
at 


Per 
Cent 


Per 
Cent 


Grams 


Grav. 

at 
15.6° C. 


Per 
Cent 


Eei 

Cent 


Grams 


Grav. 

at 
15.6° C. 


Per 

Cent 


Per 
Cent 


Grams 


15.6° C. 


by 
Weight 


by Vol- 
ume. 


per 
100 cc. 


by 
Weight 


by Vol- 
ume. 


per 
too cc. 


by 
Weight 


by Vol- 
ume. 


per 
100 cc. 


I. 0000 


0.00 


0.00 


0.00 


















0.9999 


0.05 


0.07 


0.05 


a- 9959 


2.33 


2-93 


2.32 


0.9919 


4.69 


5-86 


4-65 


8 


O.II 


0.13 


O.II 


8 


2-39 


3.00 


2-38 


8 


4-75 


5-94 


4.71 


7 


o.t6 


0.20 


0.16 


7 


2.44 


3-07 


2-43 


7 


4.81 


6.02 


4-77 


6 


0.21 


0.26 


0.21 


6 


2.50 


3-14 


2-49 


6 


4-87 


6.10 


4-83 


5 


0.26 


0.33 


Q.26 


5 


2.56 


3-21 


^-55 


5 


4-94 


6.17 


4.90 


4 


0.32 


0.40 


0.32 


4 


2.61 


3-28 


2.60 


4 


5.00 


6.24 


4-95 


3 


0.37 


0.46 


0-37 


3 


2.67 


3-35 


2.6s 


3 


5.06 


6.32 


5-OI 


2 


0.42 


0-S3 


0.42 


2 


2.72 


3-42 


2.70 


2 


5-12 


6.40 


5-07 


I 


0.47 


0.60 


0.47 


I 


2.78 


3-49 


2.76 


I 


5-19 


6.48 


5.- 14 





0-53 


0.66 


0-53 





2-83 


3-55 


2.81 





s-25 


6-55 


5.20 


0.9989 


0.58 


0-73 


0-58 


0-9949 


2.89 


3.62 


2.87 


0.9909 


5-3' 


6.63 


5.26 


8 


0.63 


0.79 


0.63 


8 


2.94 


3-69 


2.92 


8 


5-37 


6.71 


5-32 


7 


0.68 


0.86 


0.68 


7 


3.00 


3.76 


2.98 


7 


5-44 


6.78 


5-39 


6 


0.74 


0.93 


0.74 


6 


3.06 


3-83 


3-04 


6 


5-50 


6.86 


5-45 


S 


0.79 


0.99 


0.79 


5 


3.12 


3-90 


3.10 


5 


5-56 


6.94 


5-51 


4 


0.84 


1.06 


0,84 


4 


3-18 


3-98 


3.16 


4 


5.62 


7.01 


5-57 


3 


0.89 


I -13 


0.89 


3 


3-24 


4-05 


3.22 


3 


5-69 


7.09 


5-64 


3 


0.95 


1. 19 


0-9S 


2 


3-29 


4.12 


3-27 


2 


5-75 


7.17 


5-70 


I 


1. 00 


1.26 


1. 00 


■I 


3-35 


4.20 


3-33 


1 


5-81 


7-25 


5-76 





1.06 


1-34 


1.06 





3-41 


4.27 


3-39 





5-87 


7-32 


S-8i 


0.9979 


1. 12 


1.42 


1. 12 


0.9939 


3-47 


4-34 


3-45 


0.9899 


5-94 


7.40 


5-88 


8 


1.19 


1.49 


1. 19 


8 


3-53 


4-42 


3-51 


8 


6.00 


7.48 


5-94 


7 


1. 25 


1-57 


1-25 


7 


3-59 


4-49 


3-57 


7 


6.07 


7-57 


6.01 


6 


1-31 


1.65 


1-31 


6 


3-65 


4-56 


3-63 


6 


6.14 


7.66 


6.07 


5 


1-37 


1-73 


1-37 


5 


3-71 


4-63 


3.69 


5 


6.21 


7-74 


6.14 


4 


1-44 


1. 81 


1-44 


4 


3-76 


4.71 


3-74 


4 


6.28 


7-83 


6.21 


3 


1.50 


1.88 


1.50 


3 


3-82 


4.78 


3-80 


3 


6.36 


7-92 


6.29 


2 


1.56 


1.96 


1-56 


2 


3-88 


4-85 


3-85 


2 


6.43 


8.01 


6.36 


1 


1.62 


2.04 


i.6t 


I 


3-94 


4-93 


3-91 


I 


6.50 


8.10 


6.43 





1.69 


2.12 


1.68 





4.00 


5.00 


3-97 





6-57 


8.18 


6.50 


0.9969 


I-7S 


2.20 


1-74 


0.9929 


4.06 


5-08 


4-03 


0.9889 


6.64 


8.27 


6.57 


8 


1.81 


2.27 


1.80 


8 


4.IZ 


5-16 


4.09 


8 


6.71 


8.36 


6.63 


7 


1.87 


2-35 


1.86 


'7 


4.19 


S-24 


4.16 


7 


6.78 


8.45 


6.70 


6 


1.94 


2-43 


1-93 


6 


4-25 


5-32 


4.22 


6 


6.86 


8.54 


6.78 


5 


2.00 


2-51 


1-99 


5 


4-31 


5-39 


4.28 


5 


6-93 


8.63 


6.8s 


4 


2.06 


2.58 


2.05 


4 


4-37 


5-47 


4-34 


4 


7.00 


8.72 


6.92 


3 


2. II 


2.62 


2.10 


3 


4-44 


5-55 


4.40 


3 


7.07 


8.80 


6-99 


2 


2.17 


2.72 


2.16 


2 


4-50 


5-63 


4.46 


2 


7-13 


8.88 


7-05 


I 


2.22 


2-79 


2.21 


I 


4-56 


5-71 


4-52 


I 


7 20 


8.96 


7.12 





2.28 


2.86 


2.27 





4.62 


5-7^ 


4-58 





7.27 


9.04 


7.19 



TABLES 



227 



HEHNER'S TABLE FOR CALCULATING ALCOHOL FROM SPECIFIC 

GRAVITY— (Continued) 



Spec. 


Absolute AlcohoL 


Spec. 


Absolute Alcohol. 


Spec. 


Absolute AlcohoL 




















Grav. 
at 


Per 

Cent 


Per 
Cent 


Grams 


Grav. 

at 
IS.6°C 


Per 
Cent 


Per 
Cent 


Grams 


Grav. 
at 


Per 
Cent 


Per 

Cent 


Grams 


15.6° C. 


by 


by Vol- 


per 


by 


by Vol- 


per 
100 c6. 


iS-^'C 


by 


by Vol 


per 




Weight 


ume. 


100 cc. 




Weight 


ume. 




Weight 


ume. 


100 cc 


0.9879 


7-33 


9-13 


7.24 


0.9829 


10.92 


13-52 


10-73 


0.9779 


14.91 


18. 3« 


14-58 


8 


7.40 


9.21 


7-31 


8 


n.oo 


13.62 


^0.81 


8 


15.00 


18.48 


14.66 


7 


7-47 


9.29 


7-37 


7 


11.08 


13-71 


10.89 


7 


15.08 


18.58 


14-74 


6 


7-53 


9-37 


7-43 


6 


II. 15 


13-81 


10.95 


6 


15-17 


18.68 


14-83 


5 


7.60 


9-45 


7-50 


5 


11.23 


13.90 


11.03 


5 


15-25 


18.78 


14.90 


3 


7.67 


9-54 


7-57 


4 


II. 31 


13-99 


II. 11 


4 


15-33 


18.88 


14.98 


7-73 


9.62 


7-63 


3 


11.38 


14.09 


11.18 


3 


15-42 


18.98 


15-07 


2 


7.80 


9.70 


7.70 


.2 


11.46 


14.18 


11.26 


2 


15-50 


19.08 


15-14 


I 


7.87 


9.78 


7-77 


'i 


11-54 


14.27 


11-33 


I 


IS-58 


19.18 


15.21 





7-93 


9.86 


7-83 





11.62 


14-37 


II. 41 





15-67 


19.28 


15-30 


0.9869 


8.00 


9-95 


7-89 


0.9819 


11.69 


14.46 


11.48 


0.9769 


15-75 


19-39 


IS -38 


8 


8.07 


10.03 


7.96 


8 


11.77 


14.56 


11.56 


8 


15-83 


19.49 


15-46 


7 


8.14 


10.12 


8.04 


7 


11.85 


14.65 


11.64 


7 


15-92 


19-59 


15.54 


6 


8.21 


10.21 


8.10 


6 


11.92 


14-74 


11.70 


6 


i6;Oo 


19.68 


15.63 


s 


8.29 


10.30 


8.17 


5 


12.00 


14.84 


11.78 


5 


16.08 


19.78 


15-70 


4 


8.36 


10.38 


8.24 


4 


12.08 


14-93 


11.85 


4 


16.15 


19.87 


15-76 


3 


8.43 


10.47 


8.31 


3 


12.15 


15.02 


11.92 


3 


16.23 


19.96 


15-84 


2 


8.50 


10.56 


8.38 


2 


12.23 


15.12 


12.00 


2 


16.31 


20.06 


15-90 


I 


8-57 


10.65 


8.45 


I 


12.31 


15.21 


12.08 


I 


16.38 


20.15 


15-99 





8.64 


10-73 


8-52 





12.38 


;i5-30 


12.14 





16.46 


20.24 


16.06 


0.9859 


8.71 


.10.82 


8.58 


0.9809 


12.46 


15-40 


12.22 


0.9759 


16.54 


20.33 


16.13 


8 


8.79 


10.91 


8.66 


8 


12.54 


15-49 


12.30 


8 


16.62 


20.43 


16. 21 


7 


8.86 


11.00 


8.73 


7 


12.62 


15-58 


12.37 


7 


16.69 


20.52 


16.28 


6 


8-93 


11.08 


8.80 


6 


12.69 


15.68 


12.44 


6 


16.77 


20.61 


16.35 


5 


9.00 


11.17 


8.87 


5 


12.77 


15-77 


12.51 


5 


16.85 


20.71 


16.43 


4 


9.07 


11.26 


8-93 


4 


12.85 


15.86 


12-59 


4 


16.92 


*o.8o 


16.50 


3 


9.14 


"-35 


9.00 


3 


12.92 


15.96 


12.66 


3 


17.00 


20.89 


16.57 




9.21 


11.44 


9.07 


2 


13.00 


16.05 


12.74 


2 


17.08 


20.99 


16.65 


I 


9.29 


11.52 


9.14 


I 


13.08 


16.15 


12.81 


I 


17.17 


21.09 


16.74 





9-36 


II. 61 


9.22 





13-15 


16.24 


12.89 





17-25 


21.19 


16.81 


0.9849 


9-43 


11.70 


9.29 


0.9799 


13-23 


»6.33 


12.96 


0.9749 


17-33 


21.29 


16.89 


8 


9-50 


11.79 


9-35 


8 


13-31 


16.43 


13-03 


8 


17.42 


21.39 


16.97 


7 


9-57 


11.87 


9.42 


7 


13-38 


16.52 


13.10 


7 


17-50 


21.49 


17-05 


6 


9.64 


11.96 


9-49 


6 


13-46 


16.61 


i3-;i8 


6 


17.58 


21-59 


17.13 


5 


9.71 


12.05 


9-56 


5 


13-54 


16.70 


13.26 


5 


17.67 


21.69 


17.20 


4 


9-79 


12.13 


9.64 


4 


13.62 


16.80 


^3-33 


4 


17-75 


21.79 


17.29 


3 


9.86 


12.22 


9.71 


3 


13.69 


16.89 


13-40 


3 


^7-83 


21.89 


17 37 
17-46 


3 


9-93 


12.31 


9-77 


2 


13-77 


16.98 


13-48 


2 


17.92 


21.99 


I 


ro.oo 


12.40 


9-84 


I 


13-85 


17.08 


13-56 


I 


18.00 


22.09 


17-54 





10.03 


12.49 


9-92 





13.92 


17.17 


13-63 





18.08 


22.18 


17.61 


0.9839 


10.15 


12.58 


9-99 


0.9789 


14.00 


17.26 


;3-7i 


0.9739 


18.15 


2^.27 


17.68 

17-76 
17.82 


8 


10.23 


12.68 


10.06 


8 


14.09 


17-37 


13-79 


8 


18.23 


22.36 


7 


10.31 


12.77 


10.13 


7 


14.18 


17-48 


13.88 


7 


18.31 


22.46 


6 


10.38 


12.87 


10.20 


6 


14.27 


17-59 


13.96 


6 


18.38 


22.55 


17.90 


5 


10.46 


12.96 


10.28 


5 


14.36 


17.70 


14.04 


5 


18.46 


22.64 


17-97 
18.05 

18.13 
18.19 
18.27 
18.34 


4 


10.54 


13-05 


10.36 


4 


14-45 


17.81 


14-13 


4 


18.54 


22.73 


3 


10.62 


13-15 


10.44 


3 


14-55 


ir.92 


14-23 


3 


18.62 


22.82 


2 


ro.69 


13-24 


10.51 


2 


14.64 


18.03 


'4-32 


2 


18.69 


22.92 


I 


ip.77 


13-34 


IO-59 


•1 


14-73 


18.14 


^4-39 


1 


18.77 


23.01 


10.85 


13-43 


10.67 





14.82 


18.25 14.48 





18.85 


2I.I<5 



228 



APPENDIX 



HEHNER'S TABLE FOR CALCULATING ALCOHOL FROM SPECIFIC 

G1^\\ITY— {Continued) 





Absolute Alcohol. 


Spec. 


Absolute Alcohol. 


Spec. 


Absolute Alcohol. 


Spec. 
















1 


Grav. 
at 


Per 
Cent 


Per 
Cent 


Grams 


Grav. 

at 
15.6° C. 


Per 
Cent 


Per 
Cent 


Grams 


Grav. 

at 
15.6° C. 


Per 
Cent 


Per 
Cent 


Grams 


ts.e'C. 


by 


by Vol- 


per 


by 


by Vol- 


per 


by 


by Vol- 


per 




Weight 


ume. 


100 cc. 




Weight 


ume. 


100 cc. 




Weight 


vune. 


100 cc. 


0.9729 


18.92 


23-19 


18.41 


0.9679 


22.92 


27-95 


22.18 


0.9629 


26.60 


32.27 


25.61 


8 


19.00 


23.18 


18.48 


8 


23.00 


28.04 


22.26 


8 


26.67 


32-34 


25.67 


7 


19.08 


23-38 


18.56 


7 


23-08 


28.13 


22.33 


7 


26.73 


32.42 


35-73 


6 


19.17 


23-48 


18.65 


6 


23-15 


28.22 


22.40 


6 


26.80 


32-50 


25-79 


S 


19-25 


23-58 


18.73 


5 


23-23 


28.31 


22.47 


5 


26.87 


32-58 


35-85 


4 


19-33 


23.68 


18.80 


4 


23-31 


28.41 


22.54 


4 


26.93 


32-65 


25-91 


i 


19-42 


, 23-7» 


18.88 


3 


23.38 


28.50 


22.61 


3 


27.00 


32-73 


25.98 


2 


19-5° 


23.88 


18.95 


2 


23.46 


28.59 


22.69 


2 


27-07 


32..81 


26.04 


I 


19-58 


23.98 


19-03 


I 


23-54 


28.68 


22.76 


I 


27.14 


32-90 


26,10 





19.67 


24.08 


19.12 





23.62 


28.77 


22.83 





27.21 


32.98 


26.17 


0.9719 


19-75 


24.18 


19.19 


0.9669 


23.69 


28.86 


22.90 


0.9619 


27-29 


33-06 


36.25 


8 


19-83 


24.28 


19-27 


8 


23-77 


28.95 


22.97 


8 


27-36 


33-15 


26.31 


7 


19.92 


24-38 


19-36 


7 


23-85 


29.04 


23-05 


7 


27-43 


33-23 


26.37 


6 


20.00 


24-48 


19.44 


6 


23-92 


29-13 


23.11 


6 


27-50 


2,3-3^ 


26.43 


5 


20.08 


^4-58 


19-51 


5 


24.00 


29.22 


23-19 


S 


27-57 


33-39 


26.51 


4 


20.17 


24.68 


J9-59 


4 


24.08 


29.31 


23-27 


4 


27.64 


33-48 


26.57 


3 


20.25 


24-78 


19.66 


3 


24-15 


29.40 


23-33 


3 


27.71 


33-56 


26.64 


2 


20.33 


24.88 


19-74 


2 


24-23 


29-49 


23-40 


2 


27-79 


33-64 


26.71 


I 


20.42 


24.98 


19.83 


I 


34-31 


29-58 


23-48 


I 


27.80 


33-73 


26.78 





20.50 


25.07 


19.90 





24-38 


29.67 


23-55 





27-93 


33-81 


26.84 


0.9709 


20.58 


25-17 


19.98 


0.9659 


24.46 


29.76 


23.62 


0.9609 


28.00 


33-89 


26.90 


8 


20.67 


25-27 


20.07 


• 8 


24-54 


29.86 


23-70 


8 


28.06 


33-97 


^6.96 


7 


20.75 


25-37 


20.14 


7 


24.62 


29-95 


23-77 


7 


28.12 


34-04 


27.01 


6 


20.83 


25-47 


20.22 


6 


24-69 


30.-04 


23.84 


6 


28.19 


34-11 


27-07 


5 


20.92 


25-57 


20.30 


5 


24-77 


30-13 


23-91 


5 


28.25 


34.18 


27-13 


4 


21.00 


25-67 


20.33 


4 


24-85 


30.22 


23-99 


4 


28.31 


•34-25 


27.18 


3 


21. oS 


25-76 


20.46 


3 


24.92 


30-31 


24-05 


3 


28.37 


34-33 


27.24 


2 


21.15 


25-86 


20.52 


2 


25.00 


30.40 


24.12 


2 


28.44 


34-40 


27-3J 


I 


21.23 


25-95 


20.59 


1 


25-07 


30.48 


24.19 


I 


28.50 


34-47 


27.36 





21.31 


26.04 


20.67 





25-14 


30-57 


24.26 





28.56 


34-54 


37-43 


0.9699 


21.38 


26.13 


20.73 


0.9649 


25.21 


30.65 


24-32 


0.9599 


28.62 


34-6i 


37-47 


8 


21.46 


26.22 


20.81 


8 


25.29 


30.73 


24-39 


8 


28.69 


34-69 


27-53 


7 


21.54 


26.31 


20.89 


7 


25-36 


30.82 


24-46 


7 


28.75 


34-76 


37-59 


6 


21.62 


26.40 


20.96 


6 


25-43 


30.90 


24-53 


6 


28.81 


34-83 


27.64 


5 


21.69 


26.49 


21.03 


5 


25-5° 


30.98 


24-59 


5 


28.87 


34-90 


27.70 


4 


21.77 


26.58 


21.11 


4 


25-57 


31-07 


24.66 


4 


28.94 


34-97 


27.76 


3 


21.85 


26.67 


21.18 


3 


25.64 


i^'-^z 


24.72 


3 


29.00 


35-05 


27.82 


2 


21.92 


26.77 


21.25 


2 


25-71 


iT--^i 


24.79 


2 


29.07 


35-12 


27.89 


I 


22.00 


26.86 


21-33 


I 


25-79 


Zi^-3^ 


24.86 


1 


29-^3 


35-20 


27-95 





22.08 


26.95 


21.40 





25.86 


31.40 


24-93 





29.20 


35-28 


28.00 


D.9689 


22.15 


27.04 


21.47 


0.9639 


25-93 


31-48 


24.99 


0.9589 


29.27 


35-35 


28.07 


8 


22.23 


27-*'3 


21-54 


8 


26.00 


31-57 


25.06 


8 


29-33 


35-43 


28.12 


7 


22.31 


27.22 


21.61 


7 


26.07 


31-65 


25.12 


7 


29-40 


35-51 


28.18 


6 


22.38 


27-31 


21.68 


6 


26.13 


31-72 


25.18 


6 


29-47 


35-58 


28.24 


5 


22.46 


27.40 


21.76 


5 


26.20 


31.80 


25-23 


S 


29-53 


35-66 


28.30 


4 


22.54 


27.49 


21.83 


4 


26.27 


31.88 


25-30 


4 


29.60 


35-74 


38.36 


3 


22.62 


27-59 


21.90 


3 


26.33 


31.96 


25-36 


3 


29.67 


35-81 


28.43 


2 


22.69 


27.68 


21.96 


2 


26.40 


32-03 


25-43 


2 


29-73 


35-89 


28.48 


I 


22.77 


27-77 


22.01 


1 


26.47 


32.11 


25-49 


I 


29.80 


35-97 


28.54 





22.85 


27.86 


22.12 





26.53 


32.19 


25-55 





29.87 


36.04 


28.61 



TABLES 



229 



HEHNER'S TABLE FOR CALCULATING ALCOHOL FROM SPECIFIC 

GRAVITY— iConti7ttied) 



Spec. 
Grav. 

at 
i5<fir°C. 



Absolute Alcohol. 



Per 

Cent 

by 

Weight 



Per 
Cent 
by Vol- 
ume, 



Grams 
per 



Spec. 
Grav. 



iS^-C 



Absolute Alcohol. 



Per 

Cent 

by 

Weight 



Per 

Cent 
by Vol- 
ume. 



Spec. 
Grav. 



I5-6°C 



Absolute Alcohol. 



Per 

Cent 

by. 

Weight 



Per 

Cent 

by Vol 

ume. 



Grams 
per 



0.9579 



0.9569 



0.95S9 



0.9S49 



0.9539 
8 

7 
6 



29-93 
30.00 
30.06 

30 

30-17 

30.22 

30.28 

30-33 

30.39 

30.44 

30.50 
30-56 
30.61 
30.67 

30-72 
30.78 
30.83 
30.89 
30.94 
31- 

31.06 
31.12 
31-19 
31-25 

31-37 
31-44 
31-5° 
31-56 
31.62 

31.69 

31-75 
31.81 

31-87 
31-94 
32.00 
32.06 

32 
32.19 

32-25 

P-3^ 
32-37 
32.44 
32.50 
32-56 
32.62 
32.69 

32-75 
32.81 

32.87 



36.12 
36.20 
36.26 
36-3^ 
36-39 
36-45 
36.51 
36-57 
36-64 
36.70 

36.76 

36-83 

36.89 

36-95 

37-02 

37.08 

37-14 

37 

37-27 

37-34 

37-41 
37-48 
37-55 
37-62 
37-69 
37-76 
37-83 
37-90 
37-97 
38-04 

^^ o 
38.18 

38.25 
38-33 
38.40 

38-47 
38-53 
38.60 
38.68 
38.75 

38.82 
38.89 
38.96 

39-04 
39-" 
39.18 

39-25 
39-32 
39-40 
39-47 



28.67 

28.73 
28.78 
28,82 
28.88 
28.92 
28.98 
29.03 
29.08 
29.13 

29.18 
29-23 
29-27 
29-33 
29-38 

29-43 
29.48 
29-53 
29.58 
29.63 

29.69 
29-74 
29.81 
29. 86 
29.91 
29.97 
30-03 
30.09 

30.14 
30.20 

30.26 
30-31 
30-36 
30.42 
30-48 
30-53 
30-59 
30-64 
30-71 
30-77 

30. 8r 
30-87 
30-93 
30-99 
31-05 
31.10 

31-15 
31.20 
31.26 
31-32 



-9529 
8 

7 
6 

5 
4 
3 



0.9519 
8 



-9509 
8 

7 
6 

5 
4 
3 



• 9499 

8 

7 
6 

5 
4 
3 



_L 



32-94 

33-00 

33-06 

33-12 

33-^ 

33-24 

33-29 

33-35 

33-41 

33.-47 

33-53 

33-59 

33-65 

33-7.' 

33-76 

33-8'^ 

33 

33-94 

34 

34-05 

34.10 
34-14 
34-19 
34-24 
34-29 
34-33 
34-38 
34-43 
34.48 

34-5 

34-57 

34-6 

34-67 

34-71 

34-76 

34.81 

34 
34-90 
34-95 
3S-0O 

35-05 
3S-IO 
35-15 
35-20 
35-25 
35 -.30 
35-35 
35 -40 
35-45 
35-50 



39-54 
39.61 
39.68 
39-74 
39.81 

39-87 
39-94 
40.01 
40.07 
40.14 

40.20 
40-27 
40-34 
40.40 
40.47 

40.53 
40. 60 
40.67 
40.74 
40.79 

.40.84 
40.90 

40-95 
41.00 
41.05 
41. II 
41.16 

41 
41.26 

41-32 

41-37 
41.42 
41.48 
41-53 
41.58 
41.63 
41.69 
41.74 
41.79 
41. 

41.90 

41-95 
42.01 
42.06 
42.12 

42.17 
42.23 
42 .29 
42.34 
42.40 



31-38 
31-43 
31-48 
31-53 
31-59 
31-63 
31-69 
31-74 
31.80 
31.86 

31-91 
31.96 
32.01 
^2.07 
32.12 

32-17 
32.22 

32-27 
32-32 
32-37 

32.41 
32-45 
32.49 
32-54 
32-59 
32.63 

32-67 
32-71 
32-75 
32-79 

32.84 
32.88 
32.92 
32.96 
33-00 
33 -04 
33-09 
33-13 
33-17 
33-21 

32.26 
33-30 
33-34 
33-39 
33-43 
33-48 
33-53 
33 -.57 
33-61 
33-65 



0.9479 



0.9469 



0.9459 

8 

7 
6 

5 



0.9449 
8 

7 
6 

5 
4 
3 



0.9439 
8 

7 
6 

5 
4 
3 



35-55 

35-60 

35-65 

35-70 

35-75 

35 

35-85 

35-90 

35^5 

36.00 

36.06 

36 

36-17 

36.2 

36-28 

36-33 

36-39 

36.44 

36-50 

36.56 

36.61 
36-67 
36-7^ 
36.78 
36.83 

36- 

36-94 

37-00 

37-06 

37-11 

37-1? 

37-22 

37-2" 
37-33 
37-39 
37-44 
37-50 
37-56 
37-61 
37-67 



37-73 
37-78 

37-89 
37.49 
38.00 
38.06 
38.11 

38-17 
38.22 



42-45 
42.51 
42.56 
42.62 
42.67 

42-73 
42.78 
42.84 
'42-89 
42.95 

43-01 
43-07 
45-13 
43-'9 
43.26 

43-32 

43- 

43-44 

43-50 

43-56 

43-63 
43-69 
43-75 
43-81 
43-87 
43-93 
44.00 
44.06 
44-12 
44 

44.24 
44.30 
44-36 
44-43 
44.49 
44-55 
44.61 
44.67 
44-73 
44-79 

44.86 
44. 9« 

44-98 
45-04 
45-10 
45.16 
45-22 
45.28 
^5-34 
45-41 



33-70 
33-75 
33-79 
33-83 
33-88 
33-92 
33-97 
34-OI 
34-05 
34-09 

34-14 
34-^9 
34-24 
34 -23 
34-34 
34-38 
34-44 
34-48 
34-54 
34-58 

34-63 
34-69 
34-73 
34-79 
34-83 
34.88 
34-92 
34-96 
35 -o^ 
35-07 

35-1* 
35-16 
35-21 
35-26 
35-31 
35-35 
35-41 
35-46 
35-55 
35-56 

35-60 
3$ -65 
35-70 
35-75 
35-80 
35-85 
35-90 
35-95 
36-00 
36-04 



230 



APPENDIX 



HEHNER'S TABLE FOR CALCULATING ALCOHOL FROM SPECIFIC 

GRAVITY— iCo7iliniied) 





Absolute Alcohol. 




Absolute Alcohol. 




Absolute Alcohol. 


Spec. 








Spec. 








Spec. 


' 






Grav. 

at 


Per 
Cent 


Per 
Cent 


Grams 


Grav. 

at 
15.6° C. 


Per 
Cent 


Per 
Cent 


Grams 


Grav. 
at 


Per 
Cent 


Per 
Cent 


Grams 


15.6° C. 


by 


by Vol- 


per 


by 


by Vol- 


per 


15.6° C. 


by 


by Vol- 


per 




Weight 


ume. 


100 cc. 




Weight 


ume. 


xoo cc 




Weight 


ume. 


100 cc. 


0.9429 


38.28 


45-47 


36.08 


0-9379 


40.85 


48.26 


38.31 


0.9329 


43-29 


50.87 


40.38 


8 


38-33 


45-53 


36.-13 


8 


40.90 


48.32 


38-35 


8 


43 


33 


50.92 


40.42 


7 


38.39 


45-59 


36,18 


7 


40.95 


48.37 


38.39 


7 


43 


39 


50.97 


40.46 


6 


38-44 


45-65 


36-23 


6 


41.00 


48.43 


38-44 


6 


43 


43 


51.02 


40.50 


■5 


38.50 


45-71 


36.28 


5 


41.05 


48.48 


38-48 


5 


43 


48 


51-07 


40.54 


4 


38.56 


45-77 


36-33 


■4 


41.10 


48.54 


38.52 


4 


43 


52 


51.12 


40.58 


3 


38.61 


45-83 


36-38 


3 


41- 15 


48.59 


38.53 


3 


43 


57 


51-17 


40.62 


2 


38.67 


45-89 


36-43 


2 


4,1 - 20 


48.64 


38.62 


2 


43- 


62 


SI". 22 


40.66 


I 


38.72 


45-95 


36.48 


I 


41-25 


48.70 


38.66 


1 


43 


67 


51.27 


40.70 





38.78 


46.02 


36-53 





41.30 


48.75 


38.70 





43 


71 


51-32 


40.74 


0.9419 


38.83 


46.08 


36.57 


0.9369 


41-35 


48.80 


38.74 


0.9319 


43 


76 


51-38 


40.78 


8 


38.89 


46.14 


36.62 


8 


41.40 


48.86 


38.78 


8 


43 


81 


51-43 


40.81 


7 


38.94 


46.20 


36.67 


7 


41-45 


48.91 


38.82 


7 


43 


86 


51-48 


40.85 


6 


39.00 


46.26 


36.72 


6 


41-50 


48.97 


38.87 


6 


43 


90 


51-53 


40.89 


5 


39-05 


46.32 


36.76 


5 


41-55 


49-02 


38.91 


5 


43 


95 


51-58 


40.93 


4 


39-10 


46.37 


36.80 


4 


41.60 


49-07 


38-95 


4 


44 


00 


51-63 


40.97 


3 


39-15 


46.42 


36.35 


3 


41.65 


49-13 


38.99 


3 


44 


05 


51.68 


41.01 


2 


39.20 


46.48 


36.89 


2 


41.70 


49.18 


39-04 


2 


44 


09 


51-72 


41.05 


I 


39-25 


46.53 


36.94 


I 


41.75 


49-23 


39.08 


1 


44 


14 


51-77 


41.09 





39-30 


46.59 


36-98 





41.80 


49.29 


39-13 





44 


18 


51-82 


41 13 


9409 


39-35 


46.64 


37.02 


0-93S9 


41.85 


49-34 


39-17 


0.9309 


44 


23 


51-87 


41.17 


8 


39-40 


46.70 


37-07 


8 


41.90 


49 40 


39-21 


8 


44 


27 


51-91 


41.20 


7 


39-45 


46.75 


37-11 


7 


41.95 


49-45 


39-25 


7 


44 


32 


51.96 


41.24 


6 


39-50 


46.80 


37-^5 


6 


42.00 


49 50 


39-30 


6 


44 


36 


52.01 


41.28 


5 


39-55 


46.86 


37-19 


5 


42.05 


49-55 


39-34 


5 


44 


41 


52.06 


41-31 


4 


39.60 


46.91 


37-23 


•4 


42.10 


49.61 


39-38 


4 


44 


46 


52.10 


41-35 


3 


39-65 


46.97 


37-27 


3 


42.14 


49.66 


39-42 


3 


44 


50 


52.15 


41-49 


2 


39-70 


47.02 


37-32 


2 


42.19 


49.71 


39-46 


2 


44 


55 


52.20 


41-43 


I 


39-75 


47.08 


37-36 


1 


42-24 


49-76 


39-50 


I 


44 


59 


52.25 


41.47 





39.80 


47-13 


37-41 





42.29 


49.81 


39-54 





44 


64 


52.29 


41.51 


0.9399 


39-85 


47.18 


37-45 


0.9349 


42.33 


49.86 


39-58 


0.9299 


44 


68 


52-34 


41.5s 


8 


39-90 


47-- 24 


37-49 


8 


42.38 


49-91 


39.62 


8 


44 


-73 


52-39 


41.59 


7 


39-95 


47-29 


37-53 


7 


42.43 


49.96 


39.66 


7 


44 


-77 


52-44 


41.63 


6 


40.00 


47-35 


37-58 


6 


42.48 


50.01 


39-70 


6 


44 


.82 


5^-48 


41-67 


5 


40.05 


47.40 


37.62 


5 


42.52 


50.06 


39-74 


5 


44 


86 


52-53 


41.70 


4 


40.10 


47-45 


37-67 


4 


42.57 


50.11 


39-78 


4 


44 


91 


52.58 


41-74 


3 


40.15 


47-51 


37-71 


3 


42.62 


50.16 


39.82 


3 


44 


96 


52-63 


41.77 


2 


40.20 


47-56 


37-75 


2 


42.67 


50.21 


39.86 


s 


45 


.00 


?2.68 


41,81 


I 


40.25 


47.62 


37.80 


I 


42.71 


50.26 


39-90 


i 


45 


-05 


52.72 


41.85 


c 


40.30 


47,-67 


37-84 





42.76 


50-31 


39-94 





45.09 


52-77 


41.89 


0.9389 


40.35 


47-72 


37.88 


0-9339 


42.81 


50-37 


39-98 


0.9289 


45.14 


52.82 


41-93 




40.40 


47-78 


37-92 


8 


42.86 


50.42 


40.02 


8. 


45.18 


52-87 


41-97 


7 


40.45 


47-83 


37-96 


7 


42.90 


50.47 


40.06 


7 


45-23 


52-91 


42.00 


6 


40.50 


47-89 


38.00 


6 


42.95 


50.52 


40.10 


6 


45-27 


52.96 


'42.04 


5 


40.55 


47-94 


38.05 


5 


43.00 


50-57 


40.14 


5 


4St32 


■53-01 


42.08 


4 


40.60 


47-99 


38.09 


4 


43-05 


50.62 


40.18 


4 


45-36 


53-06 


42.12 


3 


40.65 


48.05 


38.13 


3 


43-10 


50.67 


40.22 


3 


45-41 


53- 10 


42.16 


2 


40.70 


48.10 


38.18 


2 


43-13 


50-72 


40.26 


2 


45-46 


53:15 


42.19 


I 


40.7s 


48.16 


38.22 


I 


43-19 


50.77 


40.30 


I 


45-50 


53.20 


42.23 





40.80 


48.21 


38.27 





43-24 


50.82 


40.34 





45-55 


53-24 


43. »7 



LISTS OF APPARATUS, REAGENTS, AND PRACTICE 

MATERIAL 

Apparatus for Use in Common 

The following instruments, pieces of multiple apparatus, 
etc. will be sufficient for a class of thirty members. 

6 Balances, analytical, each with weights, balanced watch 
glasses, and camel's-hair brush. 

I Saccharimeter and lamp (Fig. 84). 

6 Saccharimeter Tubes, glass, 200 mm., enlarged at one end 
(Fig. 86). 

I Refractometer, Abbe, with thermometer (Fig. 90). 

I Westphal Balance complete with extra float (Fig. 88). 

I Tintometer, Lovibond (Fig. 106), with slides as follows: 
Red 5.0, 2.0, 2.0, i.o, 0.5, 0.2, 0.2, 0.1. 
Yellow lo.o, 5.0, 2.0, 2.0, 1.0, 0.5, 0.2, 0.2, 0.1. 
Blue (see p. 190). 

6 Microscopes (Fig. 38), each with double nosepiece, 16 and 4 
mm. objectives, 10 X eyepiece, 6 X eyepiece, micrometer ruled 
to 0.1 mm., and stage micrometer ruled to o.oi mm. 

I Microscope with polarizing apparatus. 

I Colorimeter, Schreiner, with extra immersion and graduated 
tubes (Fig. 107). 

I Lactometer, Quevenne (Fig. 2), and cyhnder. 

1 Melting-point Apparatus (p. 188). 

2 Pipettes, Babcock, 17.6 cc. (Fig. 7). 
2 Acid Measures, Babcock (Fig. 11). 

18 Dropping Bottles, microscopic (Fig. 40). 

I Generator, Kipp, large. 

I Centrifuge, Babcock (Fig. 12). 

I Kjeldahl Digestion Stand with 13 burners complete 

(Fig. 33)- 

231 



232 APPENDIX 

I Kjeldahl Distillation Stand with 13 burners complete 
(Fig. 34)- 

1 Drying Apparatus for 1 2 determinations complete as shown 
in Fig. 26, also 18 glass drying tubes with corks for both ends 
and 18 exit tubes, 0.5 mm. bore, in corks to fit large end of 
drying tubes. 

2 Water Ovens (Fig. 6). 
I Cork Tongs. 

I Cork Borer Set (Fig. 16). v 

1 Cork Borer Sharpener (Fig. 17). 

2 Mortars, iron (Fig. 25). 

I Food Chopper, Universal (Fig. 24). 

I Funnel, copper, short stem (Fig. 27). 

I Sugar Weighing Dish, nickel (Fig. 85). 

I Can, kerosene, galvanized iron, 5 gal., with cock, for water 
tank (p. 149) 

I pair Forceps (Fig. 93). 

I Sieve with round holes about 2V in. diam., cover, and 
receiver (Fig. 23). 

Note. — At the date of writing the war conditions are such that the importa- 
tion of apparatus is difficult or impossible. The refractometer, tintometer, and 
Westphal balance may be dispensed with without serious detriment to the course. 
Even the saccharimeter is not absolutely indispensable if a visit can be arranged 
to a laboratory carrying on sugar polarizations. Substitutes for the multiple 
Kjeldahl apparatus are described on page 65. 

Apparatus for Individual Use 

In this list are included such pieces of apparatus as are re- 
quired by each student in carrying out the work of this course, 
with no allowance for breakage. 

1 Thermometer, chemical, graduated 0-100° C. 

2 Burettes, 50 cc, one with ball cock, the other with glass 
stopcock (Fig. 35). 

I Pipette, 50 cc. 
I Pipette, 25 cc. 
I Pipette, 20 cc. 



APPARATUS 233 

I Pipette, lo cc. 

I Pipette, 5 cc. 

I Pipette, 2 cc. 

I Pycnometer, lOO cc, with delivery tube to attach to 15 in. 
condenser (Figs. 99 and 100). 

I Flask, graduated, 500 cc. 

I Flask, graduated, 100 and no cc. marks. 

i Flask, graduated, 50 and 55 cc. marks. 

I Bottle, Babcock, milk. 

I Bottle, Babcock, cream, Winton, 10 to 30 per cent. 

I Bottle, Babcock, skim milk, Wagner. 

I Flask, flat bottom, ring neck, 1000 cc, with wash bottle 
fittings complete. 

I Flask, flat bottom, ring neck, 500 cc, with double-bore 
rubber stopper (Fig. 21). 

1 Flask, flat bottom, ring neck. 300 cc, with single-bore 
rubber stopper (Figs. 95 and 100). 

2 Flasks, Kjeldahl, flat bottom, short neck, 500 cc. 

2 Flasks, flat bottom, vial mouth, 30 cc, inside diameter large 
enough to admit deHvery tube of Johnson extractor with cork, 
and 4 corks (Fig. 15). 

4 Flasks, Erlenmeyer, 500 cc. 

2 Flasks, Erlenmeyer, 200 cc, and 2 single-bore rubber 
stoppers (Fig. 94). 

1 Flask, filtering, 500 cc, heavy glass with side neck and 
single-bore rubber stopper (Fig. 19). 

2 Beakers, 400 cc 
2 Beakers, 250 cc. 

2 Watch-glasses, 90 mm. 

2 Funnels, 6.5 cm. diam., for 11 cm. filters. 

2 Funnels, 11 cm. diam., for 18.5 cm. folded filters. 

2 Funnels, separatory, Squibb's, pear shape, glass stoppered, 
125 cc. 

2 Condensers, Liebig's, all glass, 15 in., and i single-bore 
rubber stopper to fit top (Figs. 21, 25, etc.) 

2 Fat Extractors, Johnson, outer tubes 175 mm. long (not 



234 APPENDIX 

including delivery tube), 26 mm. inside diam. (Fig. 15), also 
4 corks to fit top. 

2 Fat Extractors, Johnson, inner tubes, 135 mm. long, 
22 mm. outside diam., not flanged at top (Fig. 28). 

I Tube, filtering, for Gooch crucibles, 28 mm. diam. (Fig. 19). 

1 Tube, melting-point, capillary, closed at one end (p. 188). 
6 Slides, microscopic 3X1 in. 

12 Cover Glass Circles, microscopic, No. 2, f in. diam. 
4 Dishes, crystallizing, glass, low form, 38 mm. high, 60 
mm. diam. 

2 CyHnders, fat, glass, flat bottom, 15 mm. high, 10 mm. 
diam. (Fig. 93). 

2 Test-tubes. 

2 Bottles, weighing, flat bottom, without neck, ground stop- 
pered, 75 mm. high, 40 mm. diam. 

4 Bottles, narrow mouth, glass stoppered, 250 cc. (Fig. 93). 
Mouth must be large enough to admit any of the fat cyHnders 
listed above. 

I Bottle, wide mouth, 8 oz., glass stoppered for subsample. 

I Bottle, wide mouth, 8 oz. (Fig. 21). 

I Bottle, wide mouth, 4 oz. (Fig. 21). 

I Tube, bulb, connecting (Fig. 21). 

3 Tubes, connecting as shown in Fig. 2 1 . 

1 Desiccator, Scheibler, 150 mm. diam., with wire gauze 
disk (Fig. 4). 

2 Crucibles, Gooch, porcelain, 35 mm. diam. (Fig. 19). 
2 Crucibles, porcelain, 40 mm. diam. (pp. 63 and 73). 

12 Dishes, tinned lead (bottle caps), 2I in. diam., iire in. 
high (Fig. 3). 

2 Burners, Bunsen. 

2 Supports, iron, rectangular base, rod 36 in. high (Figs. 
IS, etc.). 

2 Rings, iron, for supports, 4 in. diam. (Figs. 15, etc.). 

2 Clamps, iron, double jaws, separate fasteners for supports 
(Figs. 15, etc.). 

I Support, wood, for 2 burettes (Fig. 35). 



REAGENTS 235 

I Support, wood, for 2 separatory funnels (Fig. 104). 
I Pump, filter, Chapman, 3! in., with coupling (Fig. 19). 
I Pan, enameled, quart, bottom at least 5 in. (pp. 132 and 
186). 

1 Cup, enameled, pint (water bath), and copper ring with 
2 in. hole (p. 16). 

2 Wire Gauze Squares, 5 in. 

2 Sheet Iron Squares, 5 in. (Fig. 15). 
I sq.ft. Asbestos paper. 

1 Spoon, aluminum or tin, small. 

6 ft. Tubing, rubber, for lamps and condensers. 

2 ft. Tubing, rubber, thick, for suction apparatus (Fig. 19). 

2 in. Tubing, rubber, thick, i in. inside diam., for Gooch 
crucibles (Fig. 19). 

Reagents 

The quantities given are those needed by a class of thirty 
students or else the minimum advisable to purchase. 
10 lbs. Acid, acetic, glacial, c.p. 
24 lbs. Acid, hydrochloric, sp.gr. 1.20, c.p. 
I lb. Acid, molybdic, c.p. 

7 lbs. Acid, nitric, c.p. 

100 grams Acid, phospho-molybdic crys., c.p. 

I lb. Acid, phosphoric, 85%, c.p. 

27 lbs. Acid, sulphuric, c.p. 

9 lbs. Acid, sulphuric, c.p., free from nitrogen. 

9 lbs. Acid, sulphuric, common, sp.gr. i. 82-1. 83. 

1 oz. Acid, tannic. 

3 lbs. Alcohol, amyl, c.p. 

2 gals. Alcohol, ethyl, 95%. 

I lb. Aluminum sodium sulphate, tech. 

1 lb. Ammonium chloride, c.p. 

8 lbs. Ammonium hydroxide, c.p. 

2 lbs. Asbestos, amphibole, for Gooch crucibles, washed with 
acid and guaranteed to retain copper suboxide and barium sulphate. 

I lb. Asbestos wool for milk analysis. 



236 APPENDIX 

I lb. Barium chloride, c.p. 

I lb. Bromine. 

lo lbs. Calcium carbonate, marble, lumps. 

1 lb. Carbon disulphide. 

2 lbs. Chloroform, 
lo grams Citral, c.p. 
I yd. Cloth, cheese. 

I yd. Cloth, white woolen, nun's veiling. 

I lb. Cochineal, powdered. 

I lb. Copper sulphate, crys., c.p. 

1 lb. Cotton wool. 

2 oz. Diamond ink. 

3 lbs. Ether, absolute. 

2o lbs. Ether, cone, U.S. P. 

I lb. Formaldehyde, 40%. 

5 lbs. Fuller's earth. 

I gal. Gasolene. 

I lb. Glycerine. 

I lb. Iodine, resublimed. 

I lb. Lead acetate, c.p. 

5 lbs. Lead subacetate, c.p., dry. 

5 sheets Litmus paper, neutral. 

I oz. Mercury, oxide, red, c.p. 

I oz. Phenolphthalein. 

10 grams Phenylenediamine, meta, hydrochloride. 

5 lb. Potassium bisulphate, crys., c.p. 

I lb. Potassium iodide. 

I lb. Potassium oxalate. 

§ lb. Potassium permanganate, crys., c.p. 

I lb. Pumice stone, granulated (about i mm.). 

1 oz. Silver nitrate. 

5 lbs. Sodium carbonate, crys., c.p. 

2 lbs. Sodium hydroxide, electrolytic. 
I lb. Sodium hydroxide, from Na. 

5 lbs. Sodium hydroxide, granular, 95%. 
5 lbs. Sodium potassium tartrate, crys., c.p. 



PRACTICE MATERIAL 237 

I lb. Sodium sulphide. 

I lb. Sodium thiosulphate, crys., c.p. 

J lb. Sodium tungstate. 

I lb. Sulphur, flowers. 

I spool Thread, linen, white, No. 25. 

5 sheets Turmeric paper. 

I oz. Uranium acetate. 

I oz. Vanillin. 

I lb. Zinc, granulated, 20 mesh. 

10 lbs. Zinc, mossy, coml. 

Material for Laboratory Practice 

Most of the materials may be obtained of the grocer, drug- 
gist, milkman, or feed dealer. The coal-tar colors, vanillin, 
coumarin, lemon oil, terpeneless lemon oil, potato starch, and 
cassava starch would better be ordered with the reagents from 
a dealer in laboratory supplies. The quantities are sufficient 
for thirty students. 

Dairy Products. 6 lots of i qt. Milk, i pt. Skim Milk, and 
\ pt. Cream. 2 lbs. Butter. 

Meat. 6 lots of 2\ lbs. Hamburg Steak. 

Mill Products, etc. i lb. each of Wheat Flour, Graham Flour, 
Rye Flour, Buckwheat Flour, Corn Meal (whole kernel). Oat 
Meal, Rice, Hominy, Cream of Wheat, Force, Corn Flakes, 
Grape Nuts, Beans, Wheat Bran, Rye Bran, Linseed Meal, 
and Cotton Seed Meal. 

Baking Powder, i lb. each of Royal, Horsford's, and K. C, 
Calumet, or O. K. 

Starch. 1 lb. each of Corn, Potato, and Cassava Starch. 

Unground Grains and Seeds, i lb. each of Wheat, Rye, 
Corn (maize), Oats, Buckwheat, Peas, Cotton Seed, and Flax 
Seed. 

Spices. I lb. each of ground and unground Black Pepper, 
Cayenne Pepper, Cinnamon (cassia), and Ginger. 

Alkaloidal Products. ^ lb. each of Tea, Cocoa Beans, and 
Cocoa. 2 lbs. of Coffee Beans, 2 lbs. Ground Coffee, i lb. 



238 APPENDIX 

each of Roasted Peas and Wheat ground for mixing with ground 
coffee. 

Saccharine Products. lo lbs. Sugar, granulated. 2 qts. 
each of Molasses and Karo Syrup. 4 lbs. Honey, strained. 
I qt. Raspberry or Strawberry Syrup. 10 grams each of Ama- 
ranth, Ponceau 3R, Erythrosin, Orange I, Naphthol Yellow S., 
I oz. Cudbear or other lichen color. 

Fats and Oils. 2 lbs. of Oleomargarine, i lb. each of Cocoa- 
nut Oil, Beef Tallow, Lard, and Cocoa Butter, i pt. each of 
Olive Oil, Cotton Seed Oil, Peanut Oil, Sesame Oil, and Rape 
Oil. 

Fruit Products. 6 pint bottles each of Sweet Cider, sterilized, 
and Fermented Cider, i qt. of Cider Vinegar. 

Extracts. 2 qts. Vanilla Extract, pure (or \ lb. Vanilla 
Beans for making same). 2 qts. Imitation Vanilla Extract 
made from vanillin and coumarin, colored with caramel (or i oz. 
each of the ingredients for making same), i qt. Lemon Extract 
(or 2 oz. Lemon Oil for making same), i pt. Terpeneless Lemon 
Extract (or 10 grams Terpeneless Lemon Oil for making same). 



INDEX 



Absorption of flour, 77 
Acetic acid, 4, 162 

determination, 4 
Acetyl value of fats, 160 
Acid, acetic, 4, 162 
arachidic, 140, 151 
behenic, 140, 
benzoic, 37 
boric, 25, 36 
butyric, 140, 141 
capric, 140 
caproic, 140 
caprylic, 140 
carbonic, 79 
citric, I, 162 
erucic, 140 
fatty, 140 
hypogaeic, 140 
iso-oleic, 140 
lactic, 29 
lauric, 140 
lignoceric, 140 
linolic, 140 
malic, 162 
myristic, 140 
oleic, 140 
palmitic, 140 
rapic, 140 
salicylic, 36 
stearic, 140 

sulphurous, 36, 37, 38, 178 
tartaric, 162 
Acidity of cider, 174 

flour, 77 

fruit juices, 168 

liquors, 174 

vanilla extract, 196 

vinegar, 177 

wine, 174 



Acids, fatty, 139, 140 

insoluble, 160 

saturated, 139, 140 

soluble, 160 

unsaturated, 139, 140 

volatile, 3, 31, 141, 151 
in fruits, 163 
organic, 162 
Alcohol, 4, 164, 168 
in lemon extract, 200 

liquors, 172 

vanilla extract, 196 
table, 226 
wood, 170 
Aldehydes in lemon extract, 200 

liquors, 172 
Aleurone cells, 96, 104 

grains, 109, in 
Alkaloidal foods, 3, 203 
Alkaloids, 203 
Allspice, composition of, 46 
Almond extract, 200 
Almonds, composition of, 45 
Aluminum salts in baking powder, 78, 

80 
Amides, 64 

Amido compounds, 3, 64 
Amino acids, 64 
Analysis, see Determination. 
Animal foods, i, 33 

composition of, 35 
Apparatus lists, 231, 232 
Apple juice, 165 
Apples, composition of, 45 
Araban, 77 
Arabinose, 77 
Arachidic acid, 140, 151 
Arata wool dyeing test, 137 
Arsenic in malt liquors, 1 70 



239 



240 



INDEX 



Asbestos for Gooch crucibles, 28, 40, 76, 

235 
Ash constituents, i, 31, 34 

determination, 15, 27, 30, 73, 136, 
177, 206, 208, 210 
in animal foods, i, 34, 35 

butter, 26, 27 

cheese, 30 

cocoa products, 210 

coffee, 206 

eggs, 34, 35 

fish, 34, 35 

fruit products, 177 

fruits, 45, 72, 73 

maple products, 136 

meat, 34, 35 

milk, 10, 15 

mill products, 44, 72, 73 

nuts, 45, 72, 73 

spices, 46, 72, 73 

tea, 208 

vanilla extract, 182 

vegetable foods, 2, 44, 45, 46, 72, 73 

vegetables, 45, 72, 73 

vinegar, 176 
Asparagin, 64 
Asparagus, composition of, 45 

B 

Babcock test, 18 
Baking powder, 78 

constituents, 78 

kinds of, 78 

practice samples of, 79 

reactions of, 79 

test for aluminum salts in, 80 
phosphates in, 80 
starch in, 81 
sulphates in, 80 
Baking tests for flour, 77 
Balance, 8 

Bamihl gluten test, 99 
Bananas, composition of, 45 
Bast fibers, 115, 118 
Baudouin sesame oil test, 151 
Bean starch, 89, 93 



Beans, composition of, 44 

string, composition of, 45 
Bechi cotton seed oil test, 151 
Beef, composition of cuts, 35 

stearin, 152 
Behenic acid, 140 
Belfield beef stearin test, 152 
Black pepper, composition of, 46 
microscopy of, 112, 124, 125 
Bluefish, composition of, 35 
Borax in foods, 36 

milk, 25 
Boric acid in foods, 36 

milk, 25 
Bottles, dropping, 86 

test, Babcock, 18 
Bran, rye, analysis of, 42 
composition of, 44 
microscopy of, 99, 1 24 
wheat, analysis of, 42 
composition of, 44 
microscopy of, 99, 124 
Brazil nuts, composition, of, 45 
Bromination test, 160 
Buckwheat flour, composition of, 44 

microscopy of, 103, 124 
Burettes, 8, 66 
Butter analysis, 27 
ash in, 27 
colors in, 152 
composition of, 26 
curd in, 27 
fat, 140, 142, 143, 145, 150, 152, 155. 

157 
fat in, 27 
water in, 27 
Butyric acid, 140, 141 



Cabbage, composition of, 45 
Caffeine, 3, 42, 203 
in cocoa products, 209, 210 

coffee, 204, 205 

tea, 207, 208 
Caffctannic acid in coffee, 207 
Calcium oxalate crystals, 109, 112, 122 



INDEX 



241 



Calories, 4 

calculation, 4 
Calorimeter, 4 
Capric acid, 140 
Caproic acid, 140 
Caprylic acid, 140 
Caramel in liquors, 170 
Carbohydrates, i, 2, 3$, 41, 74, 127 
Carbon dioxide in baking powder, 79 
Carnine, ^^ 
Cassava starch, 92, 93 
Catsup, 37, 177 
Cayenne pepper, composition of, 46 

microscopy of, 114, 125 
Cellulose, 2, 59, 75, 119 
Cereal products, 2, 41, 44, 93 
Chapman filter pump, 27 
Cheese analysis, 30 

ash in, 30 

composition, 29 

fat in, 30 

protein in, 30 

water in, 30 
Chestnuts, composition of, 45 
Chicory, 119, 125, 205 
Chlorine in flour fat, 7 7 
Chlorophyl, 74, 122 
Chocolate, 2, 42 

composition of, 209 

microscopy of, 120 

milk, 209 

sweet, 209 
Cholesterol, i, 161 
Cider, fermented, 165, 170 
alcohol in, 172 

sweet, see Apple juice. 
Cinnamon, composition of, 46 

microscopy of, 115, 124, 125 
Citral, 197 

determination, 198 
Citric acid, i, 162 
Cloves, composition of, 46 
Coal tar colors in butter, 152 
in fruit products, 136 
tests for, 137 
Cochineal, test for, 138 

tincture, 68 



Cocoa, 125, 209 
beans, microscopy of, 1 20 
butter, 140, 143, 145 
nibs, 209 
shells, 209 
Cocoanut oil, 140, 143, 157 
Cocoanuts, composition of, 45 
Codfish, composition of, 35 
Coffee, 2, 42, 203 
caffeine in, 204 
caffetannic acid in, 207 
composition of, 42, 204 
microscopy of, 118, 125 
substitutes, 205 
Collagen, 3s 

Color value of vanilla extract, 189 
Colorimeter, Schreiner, 193 
Colors in butter, 152 
fruit products, 136 
fruit syrups, 137, 138 
ice cream, 31 
lemon extract, 200 
tea, 207 
wine, 170 
tests for, 137, 138, 152 
Colostrum, 12 
Column cells, 105 
Condensed milk, 30 
analysis, 30 
fat in, 30 
sucrose in, 30 
Connective tissues, 33 
Cork borer, 23, 24 
sharpener, 23, 24 
cells, 115 
Corn flakes, composition of, 44 
green, composition of, 45 
meal, composition of, 44 

microscopy of, 1 24 
microscopy of, loi, 124 
starch, microscopy of, 90, 93, 103, 
124 
Cotton seed meal, composition of, 44 
microscopy of, 106 
microscopy of, 106 
oil, 106, 140, 143, 150, 161 
test for, 150 



242 



INDEX 



Coumarin, i8i, 184 

in vanilla substitutes, 184 

melting-point of, 188 

test for, 189 
Cover glasses, microscopic, 86 
Crampton and Simon palm oil test, 152 
Cream of wheat, composition of, 44 
Creatine, i, 3^, 34 
Creatinine, i, S3, 34 
Cross cells, 97, 99, no 
Crude fat, see Fat. 

fiber, see Fiber. 

protein, see Protein. 
Crystalloids, no 
Curd in butter, 27 
Cutin, 2 
Cylinder, perforated, 17 



Dairy products, 1 1 
literature of, 6 
Dalican titer test, 160 
Desiccator, 16 
Determination of: 

absorption of flour, 77 
acetyl value of fats, 160 
acidity of flour, 77 

fruit juices, 168 

liquors, 174 

vanilla extract, 196 

vinegar, 177 
alcohol in lemon extract, 200 

liquors, 172 

vanilla extract, 196 
aldehydes in lemon extract, 200 

liquors, 170 
arsenic in malt liquors, 170 
ash in butter, 27 

meat, 34 

milk, 15 

mill products, 72 

vanilla extract, 196 
caffeine in cocoa products, 210 

coffee, 205 

tea, 208 
caffetannic acid in coffee, 207 
caramel in liquors, 1 70 



Determination of carbon dioxide in 

baking powder, 79 
chlorine in flour fat, 77 
citral in lemon extract, 198 
color value of vanilla extract, 189 
coumarin in vanilla extract, 184 
crude fiber, 69 
curd in butter, 27 
dextrin in liquors, 170 
dextrose, 76 

essential oils in extracts, 200 
esters in liquors, 1 70 
ether extract in mill products, see Fat. 

spices, 59 
fat in butter, 27 

cheese, 30 

meat, 34 

milk, 18, 21 
condensed, 30 

mill products, 56 
fiber, 60 

furfural in liquors, 170 
fusel oil in liquors, 1 70 
gasoline color value of flour, 77 
gluten in flour, 77 
glycerol in liquors, 1 70 
Hanus number of fats, 152 
insoluble fatty acids, 160 
invert sugar in fruit juices, 167 
iodine number of fats, 152 

flour fat, 77 
Koettstorfer number of fats, 155 
lactose in milk, 26 
lead number of maple products, 136 
lemon oil in lemon extract, 198 
malic acid in cider, 1 70 
melting-point of coumarin, 188 

fats, 159 
moisture, see Water, 
nitrates in wine, 1 70 
nitrites in flour, 77 
nitrogen, see Protein, 
nitrogen-free extracts, 74 
normal lead number of vanilla extract, 

191 
pentosans, 77 
phosphoric acid in liquors, 1 70 



INDEX 



243 



Determination of Polenske number of 

fats, 159 
potassium sulphate in wine, 1 70 
protein in cocoa products, 210 

coffee, 206 

liquors, 170 

meat, 34 

milk, 25 

mill products, 65 

pepper, 72 
refractive index, 146 
Reichert - Meissl number of fats, 

157 
saponification number of fats, 155 
sodium chloride in wine, 1 70 
solidifying point of fatty acids, 160 
solids in fruit juices, 166 

liquors, 174 

milk, 15, 16, 25 

saccharine products, 13s 

vinegar, 177 
soluble fatty acids, 160 
specific gravity of fats and oils, 144 

milk, 14 
starch in flour, 75 
sucrose in condensed milk, 30 

fruit products, 177 

molasses, 133 

sugar, 130 

syrup, 133 

vanilla extract, 196 
sugars in liquors, 1 70 
sulphur dioxide, 38 
tannin in tea, 208 

wine, 170 
tartaric acid in wines, 170 
theobromine in cocoa products, 210 
unsaponifiable matter of fats, 161 
vanillin in vanilla extract, 184, 192 
volatile fatty acids in fats, 157 
water in butter, 27 

meat, 34 

milk, see Solids. 

mill products, 52 

saccharine products, see Solids. 

spices, 55 
Dextrin in liquors, 1 70 



Dextrose, constitution of, 127 

copper reduction by, 76, 128, 213 
Diastase, 75, 168 
Digestion apparatus, Kjeldahl, 65 
Dish, aluminum, 15 

crystallizing, 187 

nickel, 15 

platinum, 15 

tinned lead, 15 
Distilled liquors, see Liquors. 
Distilling apparatus, alcohol, 172 
Kjeldahl, 65 
sulphur dioxide, 38 
volatile fatty acids, 158 
Duplicate analyses, 15 



Eels, composition of, 35 
Eggs, I, 33, 35 

composition of, 34, 35 
Elastin, 3^ 

Embryo, 95, loi, 104, 105, no, 118 
Endosperm, 94, 102, 104, 105, 109, no, 

112, 118, 119 
Epidermis, 104, 108, no, 115, 122 
Erucic acid, 140 

Essential oils, 3, 179, 196, 200, 201 
Esters in liquors, 170 
Ether extract, see Fat. 
Extract, almond, 200 

lemon, 196, see also Lemon extract. 

orange, 200 

peppermint, 201 

spice, 201 

vanilla, 180. See also Vanilla ex- 
tract. 

wintergreen, 200 
Extraction with ether, 21, 56 
immiscible solvents, 184 
Extracts, flavoring, 179 

meat, 34 

F 

Facing of tea, 207 

Fat determination, 18, 21, 27, 30, 31, 56 
in animal foods, i, 33, 34, 35 
butter, 26, 27 



244 



INDEX 



Fat in cheese, 29, 30 
cocoa products, 210 
coffee, 206 
cream, 18 
eggs, 34, 35 
fish, 34, 35 
fruit products, 162 
fruits, 45, 55, 56 
ice cream, 31 
meat, 34, 35 
milk, II, 18, 21 
condensed, 30 
mill products, 44, 55, 56 
spices, 46, 59 
tea, 208 
vegetable foods, 2, 41, 44, 45, 46, 

55> 56 
vegetables, 45, 55, 56 
Fats, see Oils. 

Fatty acids, see Acids, fatty. 
Fehling solution, 75, 76 
Fiber, crude, constituents, 59 
determination, 60 
in cocoa products, 210 
coffee, 206 
fruit products, 162 
fruits, 45, 59, 60 
mill products, 44, 59, 60 
nuts, 45, 59, 60 
spices, 46, 59, 60 
tea, 208 

vegetable foods, 2, 41, 59, 60 
vegetables, 45, 59, 60 
Fibro-vascular bundles, 115 
Fish, I, ss 

composition of, 34, 35 
Flavoring extracts, 179 
Flax seed, see Linseed. 
Flour, absorption of, 77 
acidity of, 77 
analysis of, 77 
baking tests of, 77 
buckwheat, composition of, 44 

microscopy of, 103, 124 
composition of, 44 
graham, composition of, 44 
rye, composition of, 44 



Flour, rye, microscopy of, 99, 124 
wheat, color value of, 77 
composition of, 44 
fat, chlorine in, 77 

iodine number of, 77 
gluten in, 77, 99 
microscopy of, 99, 124 
nitrites in, 77 
starch in, 44, 75 
Folin and Denis vanillin method, 192 
Food analysis, limitations, 5 
literature, 5 
province, 5 
chopper, 48 

technology literature, 6 
Foods, animal, i 
microscopy of, 83 
mineral, 4 
vegetable, 2, 41 
Force, composition of, 44 
Fore milk, 1 2 
Foreign leaves in tea, 208 
Formaldehyde in milk, 20 
Fowls, composition of, 35 
Fructose, d, see Levulose. 
Fruit juices, acidity of, 168 
solids in, 164, 166 
sugar in, 163, 167 
products, 162 

analysis of, 164, 177 
preservatives in, 177 
syrups, colors in, 137, 138 
Fruits, 2, 43, 45, 162 
analysis of, 43, 163 
canned, 177 
composition of, 45 
dried, 177 
Funnel, separatory, 185 
Furfural in liquors, 1 70 
Fusel oil in liquors, 1 70 

G 

Gasoline color value of flour, 77 
Gelatin, 33 

Ginger, composition of, 46 
microscopy of, 116, 125 
Gliadin, 98 



INDEX 



245 



Globoids, 112 

Glucose, commercial, 133 

d, see Dextrose. 
Gluten, 77, 98 
Glutinin, 98 
Glycerol in fats, 139 

liquors, 170 
Glycogen, i, 33 
Gooch crucible, 27, 28 
Graham flour, composition of, 44 
Grape nuts, composition of, 44 
Grapes, composition of, 45 
Green corn, composition of, 45 
Grits, composition of, 44 
Guanine, ^s 
Gums, 2, 74 
Gunning -Arnold-Kjeldahl method, 72 

H 

Hairs, 97, loi, 108, 122 
Halibut, composition of, 35 
Halphen cotton seed oil test, 150 
Hanus iodine number method, 152 
Henneberg crude fiber method, 60 
Hess and Prescott vanillin and cou- 

marin method, 184 
Hiltner citral method, 198 
Hominy, composition of, 44 
Homogenized oils, 31 
Honey, invert sugar in, 133 

polarization of, 134 

solids in, 135 
Hiibl iodine number method, 152 
Hypogaeic acid, 140 



Ice cream, 30 

analysis of, 31 

colors in, 31 

fat in, 31 

homogenized oils in, 31 

preservatives in, 31 

thickeners in, 31 
Insoluble fatty acids, 160 
Intercellular spaces, 98, 122, 123 
Inversion of sucrose, 131, 134 



Invert sugar, copper reduction by, 128, 
167 
determination, 131, 161, 213 
Iodine number, 3, 152 
Iso-oleic acid, 140 



Jellies, 177 

Johnson fat extractor, 21, 22, 56, 57 
Kjeldahl apparatus, 65, 66 



KJeldahl nitrogen method, 65 
Koettstorfer saponification number 
method, 155 



La Wall and Bradshaw benzoate method, 

178 
Lactic acid, 29 
Lactometer, 14 
Lactose determination, 26, 213 

in milk, i., 26 
Lard, 143, 145, 150 
Laurie acid, 140 
Leach coumarin test, 189 
Lead number, 136 
Leaves, foreign, in tea, 208 

spent, in tea, 208 
Lecithin, i 
Leffmann and Beam volatile fatty acids 

method, 157 
Legumes, 2, 64 
Lemon extract, 196 

alcohol in, 200 

aldehydes in, 200 

citral in, 198 

colors in, 200 

composition of, 197 

lemon oil in, 197, 198 

practice material, 197 

terpeneless, 197 
oil, 196 

in lemon extract, 197, 198 

terpeneless, 197 
Lettuce, composition of, 45 
Levulose, 127, 128 



246 



INDEX 



Lignin, 2, 59 
Lignoceric acid, 140 
Limonene, 196 
Linolic acid, 140 
Linseed meal, composition of, 44 
microscopy of, no, 124 

microscopy of, no 

oil, 140, 152 
Liquors, 162 

distilled, composition, 170, 171 

malt, composition, 170, 171 

preservatives in, 170 

wood alcohol in, 170 
Lists, apparatus, 231 

practice material, 237 

reagents, 235 
Lobster, composition of, 35 
Lovibond tintometer, 189 

M 

Mace, composition of, 46 
Maize, see Corn. 
Malic acid, 162 
Malt liquors, see Liquors. 
Maltase, 168. 
Maltose, 75, 168, 213 
Maple products, 135 
Material, practice, 237 

alkaloidal products, 42, 93, 205 

baking powders, 79 

dairy products, 14, 26 

fats and oils, 142 

flavoring extracts, 183, 197 

fruit products, 165 

list, 237 

meat, 38 

microscopic, 92, 93 

mill products, 42, 93 

saccharine products, 133, 136 

spices, 42, 93 

starches, 92 
Maumene test for oils, 160 
Meal, corn, composition of, 44 

microscopy of, 102, 124 
cotton seed, composition, 44 

microscopy of, 106 
linseed, composition of, 44 



Meal, linseed, microscopy of, no 
oat, composition of, 44 
microscopy of, loi, 124 
Meat, I, S3, 34, 35 
analysis, 34 
composition of, 34, 35 
extracts, 34 
Melting-point of coumarin, 188 

fats, 159 
Methods, see Determination and Test. 
Micrometer, 85 

calibration of, 86 
Microscope, 84 

Chamot polarizing, 85 
construction of, 84 
Microscopic accessories, 85 

mount, 87, 88 
Microscopy of bean starch, 93 
buckwheat, 103, 124 
cassava starch, 93 
cinnamon, 115, 124, 125 
cocoa, 120, 125 
coffee, 118, 125 
corn, loi 

starch, 93, 103, 124 
cotton seed, 106 
ginger, 116, 125 
linseed, no 
oat starch, 93, 1 24 
oats, 100 

peas, 105, 124, 125 
pepper, black, 112, 124, 125 
Cayenne, 114, 125 
white, 112, 124, 125 
potato starch, 93 
rye, 99, 124 
starches, 88 
tea, 122 

vegetable foods,, 83, 93 
wheat, 94, 124 
starch, 93, 98, 124 
Milk, n 

analysis, 14, 15, 16, 18, 21, 25 
boron compounds in, 25 
chocolate, 209 
composition, colostrum, 12 
cow's, II 



INDEX 



247 



Milk, composition, goat's, ii 
woman's, ii 

condensed, see Condensed milk. 

fat in, 18, 21 

fore, 12 

formaldehyde in, 20 

lactose in, 26 

preservatives in, 20, 25 

protein in, 25 

sampler, 13 

sampling, 13 

specific gravity, 14 

standards, 12 

strippings, 12 

total solids in, 15, 16, 25 
MiU products, 41 

ash in, 72, 73 

composition of, 44 

crude fiber in, 59, 60 

fat in, 55, 60 

nitrogen-free extract in, 74 

pentosans in, 77 

protein in, 63, 65 

starch in, 75 

water in, 50, 52 
Mince meat, 177 
Mineral foods, 4 
Mitchell lemon oil methods, 198 
Moisture, see Water. 
Molasses, analysis of, 133 

solids in, 135 
sucrose in, 133 
Mortar, iron, 49 
Mounting, 87 
Munson and Walker sugar method, 76 

table, 213 
Muscle fiber, ^^ 
Mustard oil, 140, 155 
Mutton, composition of, 35 

tallow, 143 
Mycoderma acdl, 1 75 
Myosin, 33 
Myristic acid, 140 



N 



Nitrates in wine, 170 
Nitrites in flour, 77 



I Nitrogen, see Protein. 
Nitrogen-free extract, constituents, 2 
determination, 74 
in cocoa products, 210 
coflfee, 206 
fruit products, 162 
fruits, 45, 74 
miU products, 44, 74 
nuts, 45, 74 
tea, 208 

vegetable foods, 2, 41, 44, 45, 74 
vegetables, 45, 74 
Normal lead number of vanilla extract, 

191 
Nutmegs, composition of, 46 
Nutrition, 6 

literature, 6 
Nuts, 2, 43, 45 
analysis of, 43 
composition of, 45 

O 

Oat meal, composition of, 44 
microscopy of, loi, 124 
starch, 90, 93, loi, 124 
Oats, microscopy of, 100, 124 
Oil, cocoanut, 140, 143, 157 

cotton seed, 106, 140, 143, 150, 161 
lemon, 196 

terpeneless, 197 
linseed, 106, 140, 152 
mustard, 140, 155 
olive, 140, 143 
palm nut, 140, 152 
peanut, 140, 143, 151 
poppy seed, 140 
rape, 140, 155 
seed products, 42, 44, 106 
analysis of, 42 
composition of, 44 
seeds, 2, 106 
sesame, 140, 143, 151 
sunflower, 140 
whale, 161 
Oils and fats, 139 

acetyl value of, 160 



248 



INDEX 



Oils and fats, acids of, 140 
Baudouin test, 151 
bromination test, 160 
cholesterol in, i, 161 
constants of, 141, 143 
constituents of, 139 
cotton seed oil in, 150 
halogenation of, 139, 152 
Halphen test, 150 
Hanus number of, 152 
hydrogenation of, 161 
insoluble fatty acids in, 160 
iodine number of, 3, 152 
Koettstorfer number of, 155 
literature of, 6 
Maumene test, 160 
melting-point of, 159 
oxidation of, 139 
Polenske number of, 159 
practice material, 142 
qualitative tests, 150, 151 
refractive index of, 3, 146 
Reichert-Meissl number of, 157 
saponification number of, 3, 155 
saponification of, 140 
sesame oil in, 151 
sitosterol in, 3, 161 
soluble fatty acids in, 160 
specific gravity of, 144 
titer test of, 160 
unsaponifiable matter in, 161 
volatile fatty acids in, 3, 31, 157 

Oils, essential, see Essential Oils. 

Oleic acid, 139, 140 

Olive oil, 140, 143 

Onions, composition of, 45 

Orange extract, 200 

Oranges, composition of, 45 

Oven, water, 17 

Oysters, composition of, 35 



Palisade cells, 105, 108 
Palm nut oil, 140, 152 

test for, 152 
Palmitic acid, 139, 140 
Pancreatin, 75 



Patrick test for ice cream thickeners, 31 
Paul method for ice cream fat, 31 
Peaches, composition of, 45 
Peanut butter, composition of, 44 
oil, 140, 151 

constants of, 143 

test for, 152 
Peanuts, composition of, 45 
Peas, microscopy of, 105, 124, 125 

green, composition of, 45 
Pecans, composition of, 45 
Pentosans, 3, 75, 77 
Pepper, black, composition of, 46 

microscopy of, 112, 124, 125 
Cayenne, composition of, 46 

microscopy of, 114, 125 
white, composition of, 46 

microscopy of, 112, 124, 125 
Peppermint extract, 201 
Pericarp, 94, 98, 103 
Perisperm, 96, 109, 112 
Phosphates in baking powder, 78, 80 
Phosphoric acid in liquors, 170 
Photosynthesis, 122 
Phytosterols, 3 
Piperine, 56, 72, 114 
Plumule, loi 
Polariscope, 128 
Polarization of honey, 133 

Karo syrup, 133 

light, 85, 129 

molasses, 133 

sucrose, 130 
Polenske number, 159 
Poppyseed oil, 140 
Pork, composition of, 35 
Potassium sulphate in wine, 170 
Potato starch, 89, 91, 93 
Potatoes, composition of, 45 
sweet, composition of, 45 
Preservatives, 31, 36, 38, 177 
in fruit products, 177 

ice cream, 31 

liquors, 170 

milk, 20, 25 

wines, 170 
Preserves, 177 



INDEX 



249 



Protein determination, 25, 30, 65, 72, 
206, 208, 210 
standard solutions, 70 
in animal foods, i, 35 
butter, 26, 27 
cheese, 29, 30 
cocoa products, 210 
coffee, 206 
eggs, 34, 35 
fish, 34, 35 
fruit products, 162 
fruits, 45, 65 
liquors, 170 
meat, 34, 35 
milk, 10, 25 
mill products, 44, 65 
nuts, 45, 65 
pepper, 72 
spices, 46, 72 
tea, 208 
vegetable foods, 2, 41, 44, 45, 46, 

65, 72 
vegetables, 45, 65 
nature of, 63 
Proteins, see Protein. 
Ptyalin, 75 



Quevenne lactometer, 14 



R 

Radicle, loi 
Rape oil, 140, 155 
Rapic acid, 140 

Raspberries, composition of, 45 
Reagent list, 235 
Refractive index, 3, 146 
Refractometer, 146 
Reichert-Meissl number, 157 
Renard peanut oil test, 151 
Resin cavities, 109 
Rice, composition of, 44 
Richmond milk scale, 25 
Robin cochineal test, 138 
Roese-Gottlieb fat method, 30 
Rye, bran, composition of, 44 



Rye, bran, microscopy of, 99, 124 
flour, composition of, 44 
microscopy of, 99, 124 
microscopy of, 99 



Saccharimeter, 1 28 
Saccharine products, 127 

analysis of, 128, 133, 135 

literature of, 6 
Saccharomyces, 78, 168, 169 
Sachsse starch conversion method, 75 
Salicylic acid, 36 
Salmon, composition of, 35 
Sample, care of, 49 

drawing, 13, 46 

preparing, 26, 48 
Sampling, 13, 46 

tube, 13, 47 
Saponification number, 3, 155 
Sarcolemma, 33 
Saturated fatty acids, 139, 140 
Scallops, composition of, 35 
Schreiner colorimeter, 193 
Scovell milk sampler, 13 
Scutellum, 95, 102 
Sesame oil, 140, 143, 151 

test for, 151 
Shad, composition of, 35 
Short method for fat in cheese, 30 
Sieve for samples, 48 
Sitosterol, 3, 161 
Slides, microscopic, 86 
Sodium benzoate, 36, 178 

chloride, 170 
Solidifying point of fatty acids, 160 
Solids, total, calculation, 25 
determination, 15, 16 

in fruit products, 164, 166 
liquors, 174 
milk, 15, 16 

calculation, 25 
saccharine products, 135 
vinegar, 177 
Soluble fatty acids, 160 
Soxhlet fat extractor, 21, 22 



250 



INDEX 



Specific gravity determination, 14 
of fats and oUs, 144 
milk, 14, 25 
Spermoderm, 96, 104, 105, 107, no, ill 
Spice extracts, 201 
Spices, 2 

analysis of, 43, 55, 59, 72 
composition of, 46 
ether extract of, 59 
protein in, 72 
water in, 55 
Spongy parenchyma, 98, 104 
Squibb burette, 67 
Starch, 2, 3, 41, 74, 75. 88 
bean, 89, 93 
buckwheat, 104 
cassava, 92, 93 
chemical properties of, 74 
cinnamon, 116 
cocoa, 121 
com, 90, 93, 124 
curcuma, 89 
determination, 75 
ginger, 118, 125 
grains, 88 

aggregates of, 92, 93 
form of, 90, 93 
hilum of, 9I; 93 
polarization crosses of, 92, 93 
rings of, 91,93 
size of, 92, 93 
table of, 93 
in baking powder, 78, 81 
chocolate, 121, 209 
flour, 75 

vegetable products, 93 
microscopic characters of, 88 
nature of, 74, 88 
oat, 90, 93 
pea, 106 
pepper, 114, 124 
potato, 89, 91, 93 
properties of, 74, 88 
rye, 99 

wheat, 89, 93, 98 
Starches, microscopy of, 188, 124 
Stearic acid, 139, 140 



Stone cells, 112, 115, 119, 122 
Strawberries, composition of, 45 
Strippings, milk, 12 
Suberin, 2, 59, 116 
Sucrose, characters of, 127 
constitution of, 127 
in condensed milk, 30 
fruit products, 162, 167 
molasses, 133 
sugar, 130 
syrup, 133 
vanilla extract, 196 
inversion of, 127, 131 
polarization of, 130 
Sugar, analysis of, 130 
invert, see Invert sugar, 
polarization of, 130 
sucrose in, 130 
Sugars, 2, 3, 33, 74, 127, 161, 167 

in liquors, 1 70 
Sulphates in baking powder, 78, 80 
Sulphur dioxide, 36, 37, 38, 178 
determination, 38 
in fruit products, 178 
meat, 37, 38 
Sulphurous acid, see Sulphur dioxide. 
Sunflower oil, 140 
Sweet potatoes, composition of, 45 
Syrup, fruit, 136 

colors in, 137, 138 
Karo, 133 
solids in, 135 
sucrose in, 133 
maple, 135 
analysis of, 135 



Table, alcohol from specific gravity, 226 
dry substance from refractive index, 

224 
lactometer temperature corrections, 

211 
refractometer readings, 222 
sugars from cuprous oxide, 213 
temperature corrections for dry sub- 
stance from refractive index, 225 



INDEX 



251 



Table, total solids from lactometer 

readings and fat, 212 
Tables, calculation, 211 
Tallow, 143 
Tannin in tea, 208 

wine, 170 
Tartaric acid, 162 
Tea, 2, 207 

analysis of, 208 
caffeine in, 207, 208 
colors in, 207 
composition of, 42, 207 
facing of, 207 
foreign leaves in, 208 
microscopy of, 122 
spent leaves in, 208 
tannin in, 208 
Test, baking, for flour, 77 
Baudouin for sesame oil, 151 
Bechi, for cotton seed oil, 151 
bromination, for oils, 160 
Crampton and Simon, for palm oil, 

152 
Dalican's titer, 160 
for aluminum salts in baking powder, 
80 
beef stearin, 152 
borax in milk, 25 
boric acid in milk, 25 
colors in butter, 152 
fruit products, 137, 138 
ice cream, 31 
lemon extract, 200 
tea, 207 
\\'ine, 170 
cotton seed oil, 150 
coumarin, 189 
facing of tea, 207 
foreign leaves in tea, 208 
formaldehyde in milk, 20 
homogenized oil in ice cream, 31 
palm oil in butter, 152 
peanut oil, 152 

phosphates in baking powder, 80 
preservatives in fruit products, 177 
ice cream, 31 
liquors, 170 



Test for preservatives in milk, 20, 25 
wines, 170 
sesame oil, 151 
spent leaves in tea, 208 
starch in baking powder, 80 

vegetable products, 93 
sulphates in baking powder, 80 
thickeners in ice cream, 31 
wood alcohol in liquors, 170 
Halphen, for cotton seed oil, 150 
Leach, for coumarin, 189 
Maumene, 160 

Patrick, for ice cream thickeners, 31 
Renard, for peanut oil, 151 
titer, 160 
Theobromine, 3, 203 

in cocoa products, 209, 210 
Thickeners, ice cream, 31 
Tintometer, Lo\abond, 189 
Titer test, 160 

Tomatoes, composition of, 45 
Tonka beans, 181 
Trout, composition of, 35 
Tube cells, 98, 103 
Turnips, composition of, 45 

U 

Unsaponifiable matter of fats, 161 
Unsaturated acids, 139, 140 



Vanilla beans, 180 
extract, 180, 181 

acidity of, 196 

adulteration of, 188 

alcohol in, 196 

ash of, 196 

color value of, 189 

composition of, 182 

coumarin in, 184 

normal lead number of, 191 

practice material, 183 

preparation of, 182 

substitutes for, 183 

vanillin in, 184 
Vanillin, 4, 181 
colorimetric method, 192 



252 



INDEX 



Vanillin, gravimetric method, 184 

in vanilla beans, 180 

extracts, 182, 184, 192 
substitutes, 184, 192 
Veal, composition of, 35 
Vegetable foods, 2, 41 

microscopy of, 83, 93 
Vegetables, 2, 43, 45 

analysis of, 43 

composition of, 45 
Vessels, 113, 118, 120 
Villavecchia and Fabris sesame oil test, 

151 
Vinegar, 162 

acidity of, 177 

cider, 174 

composition of, 176 

distilled, 174 

glucose, 17s 

malt, 174 

manufacture of, 175 

molasses, 175 

solids in, 177 

sugar, 17s 

wine, 174 
Volatile fatty acids, 3, 31. ^57 

W 

Wagner skim milk test bottle, 19 
Walnuts, composition of, 45 
Water determination, 34, 50, 52 
in animal foods, i, 34, 35 

butter, 26, 27 

cheese, 29, 30 

cocoa products, 210 

coffee, 206 

eggs, 34, 35 

fish, 34, 35 

fruit products, 162 

fruits, 45 

meat, 34, 35 

milk, II, 15 

mill products, 44, 50, 52 

nuts, 45 

saccharine products, 135 

spices, 46, 55 



Water in tea, 208 

vegetable foods, 41, 44, 45, 46, 

50. 52 
vegetables, 45, 47 
oven, 17 
Watermelons, composition of, 45 
Weighing bottle, 60 
Westphal balance, 144 
Whale oil, 161 

Wheat bran, composition of, 44 
microscopy of, 99, 124 
flour, composition of, 44 
microscopy of, 99, 1 24 
starch in, 75, 99 
microscopy of, 94, 1 24 
starch, 89, 93, 98, 124 
White fish, composition of, 35 
pepper, composition of, 46 
microscopy of, 112, 124, 125 
Wine, 168 
colors in, 1 70 
composition of, 171 
constituents of, 1 70 
fermentation, 168 
preservatives in, 170 
Wintergreen extract, 200 
Winton and Lott normal lead number 
method, 191 
cream test bottle, 19 
Wood alcohol, test for, 170 



X 



Xanthine, 33 

bases, i, 33, 34 
Xylan, 77 
Xylose, 77 



Yeast, 78 

plants, 73, 168, 169 



Zein, 102 
Zoosterols, i 
Zymase, 168 



